the rising cost of a healthy diet...the rising cost of a healthy diet: changing relative prices of...
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The rising cost of a healthy dietChanging relative prices of foods in high-income and emerging economies
Steve Wiggins
Sharada Keats
with Euna Han
Satoru Shimokawa
Joel Alberto Vargas Hernández
Rafael Moreira Claro
Report May 2015
Overseas Development Institute203 Blackfriars RoadLondon SE1 8NJ
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ISSN: 2052-7209
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• Inhighincomecountriesoverthelast30yearsitseemsthatthecostofhealthyitemsinthediethasrisenmorethanthatoflesshealthyoptions,therebyencouragingdietsthatleadtoexcessweight.
• Itseemsthesamemayapplyinemergingeconomies,suchasBrazil,China,KoreaandMexico,wherepricesoffruitandvegetableshavebeenrisingmorethanmostotherfoods,includingenergy-denseprocessedfoods.
• Astrongcaseemergesforusingtaxesandsubsidiestooffsetthesechangestoencouragemoreconsumptionofhealthyfoodsandlessofunhealthyitems.
Key messages
Contents
Abbreviations & Glossary 6
Acknowledgements 6
Summary 7
1. Introduction 11
2. Research questions and objective 16
3. What is already known? 20
3.1 United States 21
3.2 United Kingdom 29
3.4 Brazil 34
3.5 China 36
3.6 Republic of Korea 36
3.7 Mexico 37
3.8 Summary of literature from emerging economies 38
4. Data and methods 39
5. Results of analysis: price movements 42
5.1 Brazil 43
5.2 China 44
5.3 Republic of Korea 45
5.4 Mexico 46
5.5 United Kingdom 47
5.6 Comparative analysis 48
6. Conclusion and discussion 50
6.1 Changing prices 51
6.2 Do prices matter … and might taxes work? 51
References 54
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The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 5
Figures
Figure A: Estimated average annual price changes from 1990 10
Figure 1A1: Foresight’s causal map of overweight and obesity clustered by type of driver 13
Figure 1A2: Extract from Foresight’s causal map of overweight and obesity 13
Figure 1.1: Prevalence of adult overweight and obesity in four countries plus the UK and USA, 1980–2008 14
Figure 1B1: Average diets, six countries, 2010, standardised scores 16
Figure 1B2: Changes in consumption of healthy and unhealthy foods, six countries, 1990–2010, changes to
standardised scores 16
Figure 2A1: Energy density of selected healthy and less healthy snacks, USA, kcal per 100 grams 19
Figure 3.1: Prevalence of overweight and obesity, USA, by age and sex, 2011–12 22
Figure 3.2: Relationship between cost of per unit of energy and energy density for 372 foods in Seattle area
supermarkets, 2006 23
Figure 3.3: Energy density and price per calorie for selected snack foods, fruit and vegetables, USA, 2008 23
Figure 3.4: Price indices for selected foods and beverages in the USA, 1980–2010 24
Figure 3.5: Long-term average annual changes in retail prices for selected foods in the USA 25
Figure 3.6: Fruit and vegetables and ‘junk’ food, unit values and corrected prices relative to total food 30
Figure 3.7: Contribution of different food groups to daily diet costs of healthiest and least healthy group of eaters, adult
women, UK, 1995–98 31
Figure 3.8 Diet costs (per calorie) and energy density, Scotland, 2011 32
Figure 3A1: Kcal changes associated with adjusting meals to healthier options 33
Figure 3A2: Cost of different diets from three types of shop 33
Figure 3.9: Proportion of energy from different food groups, urban household purchases, Brazil, 1996–2009 35
Figure 3.10: Cost per kilocalorie for different food groups in Brazil 36
Figure 3.11: Cooking oil prices, China, 1991–2006 37
Figure 3.12: Vegetable consumption in Republic of Korea, 1969–2009, grams per person per day 38
Figure 3.14: Consumption of soft drinks per person per day, USA, UK, Mexico, Brazil, Korea and China, 2008 38
Figure 3.13: Annual sales of selected ultra-processed foods and drinks, 12 Latin American countries, 1999–2013 38
Figure 5.1: Price of selected foods, São Paulo, Brazil, 1980–2009 44
Figure 5.2: Price of selected foods, China, urban areas, 1989–2006 45
Figure 5.3: Prices of selected foods, Republic of Korea, 1975–2013 46
Figure 5.4: Prices of selected foods, Mexico, 1980–2014 47
Figure 5.5: Prices of selected foods, United Kingdom, 1974–2012 48
Figure 5.6: Estimated average annual price change from 1990 50
Tables
Table 2.1: Causal chain from costs of food to consumption, obesity and ill health 18
Table 3.1: US own-price elasticity of demand, by food and beverage category, 1938–2007 26
Table 3.2: Own-price elasticity of demand for four food groups in the USA, 2007–12 26
Table 3.3: Estimates of food price elasticity in the UK, long-run 32
Table 4.1: Food prices analysed for each food group and country 41
Table 4.2: Data sources and deflators used for country cases 41
Table 5.1: Results of log-linear regression of time on prices 49
Boxes
Box 1A: Mapping drivers of overweight and obesity: spaghetti junctions ahead 13
Box 1B: Changing diets in the four countries, UK and USA 16
Box 2A: Energy density of foods 19
Box 3A: Cheap eats and healthy treats: affordable for families of obese children in the UK? 33
Box 3B: Marketing of processed food in Brazil 35
Box 6A: How feasible are taxes on foods? 54
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The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 7
Abbreviations & GlossaryBLS US Bureau of Labour Statistics
BMI Body Mass Index, body mass compared to square of height, kg/m2. BMI of 25 or more indicates overweight, 30 or more indicates obese
CPI Consumer Price Index
Eatwell Plate UK government guide to the composition of a healthy diet
Energy density A measure of calories per unit of food
FAFH Food away from home – food consumed outside people’s homes as in restaurants etc.
FAO Food and Agriculture Organizsation of the United Nations
GDP Gross Domestic Product
HIC High-Income Country
LIC Low-Income Country
MIC Middle- Income Country
Nutrient density A measure of how many ‘healthy’ nutrients are in a food, usually by weight
Potato chips US term, the same as UK potato crisps
Prices, constant or real Nominal prices from which inflation in general price levels have been removed, either by use of a consumer price index or GDP deflator
Prices, indices Prices expressed as ratio of those at a base year, when values are usually set to 100. Indices may or may not be adjusted for inflation. The price indices constructed in this paper have been adjusted for inflation.
Prices, nominal Prices as observed at a given time, with no adjustment for inflation
SNAP Supplemental Nutrition Assistance Program (USA)
SSB Sugar-sweetened beverage (or ‘soda’ in US English)
UMIC Upper Middle Income Country
USDA United States Department of Agriculture
WCRF World Cancer Research Fund
AcknowledgementsManythankstothefollowingfortheircontributiontothisreport:
• ForChina,thereportusesdatafromtheChinaHealthandNutritionSurvey(CHNS),sowethanktheNationalInstituteofNutritionandFoodSafety,ChinaCenterforDiseaseControlandPrevention,CarolinaPopulationCenter(5R24HD050924),theUniversityofNorthCarolinaatChapelHill,theNIH(R01-HD30880,DK056350,R24HD050924,andR01-HD38700)andtheFogartyInternationalCenter,NIHforfinancialsupportfortheCHNSdatacollectionandanalysisfilesfrom1989to2011andfuturesurveys,andtheChina–JapanFriendshipHospital,MinistryofHealthforsupportforCHNS2009;
• ForKorea,HeejoKuandJae-eunMyungprovidedexcellentresearchassistance; • ForMexico,DraAlejandraDonajíBenítezArciniega(UAEMexMedicineFaculty)providedvaluablesupport; • FumiakiImamura(Cambridge)andcolleagueskindlysupplieddataonchangingdietsinthefourcountries; • CorinnaHawkes(WCRF)peerreviewedthereport,andherdetailedandincisivecommentsonanearlierversionhelpedtosharpenthethinking;and,
• DeborahEadecopy-editedthereport.
ThisreportformspartoftheODIproject‘Shockwatch:managingriskandbuildingresilienceinanuncertainworld’,whichissupportedbytheUKDepartmentforInternationalDevelopment(DFID).
Theinterpretationsandopinionsexpressedinthereportarenotnecessarilythoseoftheabovementionedpersons,noroftheOverseasDevelopmentInstitute.Themainauthorsaresolelyresponsibleforanyerrorsandomissions.
Summary
Motivations and questionsIn2014ourpreviousstudy‘FutureDiets’(KeatsandWiggins2014)describedhowacrosstheworldanincreasingshareofthepopulationisoverweightandobese,withtherateofincreaseparticularlypronouncedindevelopingcountries.Nonation,however,hasstemmedtherisingratesofpeoplewhoareoverweightandobese.Effectivepoliciestocombatobesityhaveyettobeproved,ifonlybecausenocountryhasyettestedasufficientlycomprehensivesetofpolicies.Thecausesofexcessweightaremultiple,includingrisingincomes,urbanisationandmoresedentaryoccupations,theinfluenceofmediaandadvertising,andchangingrelativepricesofdifferentfoods.Thislastelementisthefocusofthisreport.
Thereportstartsfromtwoworkinghypotheses:
a.Whentherelativepricesoffoodschange,peoplewillconsumemoreoffoodsthathavebecomerelativelylessexpensive,andlessofthosethathavebecomerelativelymoreexpensive.Peopleonlowincomesareexpectedtobemoresensitivetopricesthanthoseonhigherincomes;and,
b.Whenconsumptionoffoodswithhighcaloriecontentperunitweight(energy-densefoods)increasesattheexpenseoffoodthatislessdenseinenergy,wemayexpecttoseeasignificantincreaseintheprevalenceofoverweightandobesepeople.
Ifthesehypothesesarecorrect,theywouldsuggestthatusingtaxesandsubsidiestoinfluencedietsislikelytobeeffective.
Tothebestofourknowledge,thereisnoexistingstudythatcomparesthechangingcostsoffoodsfromseparatefoodgroupsacrossasampleofdevelopingandemergingeconomies.Thereportfocusesonfourcountries:threeupper-middle-incomecountries(UMICs)–Brazil,ChinaandMexico;andonehigh-incomecountry(HIC),theRepublicofKorea,whichwasstilladevelopingcountryin1990.Theyhavebeenchosensincetheyrepresentemergingeconomiesthataregrowingfasterthanmostindustrialisedcountries,andwheresince1990significantchangesmaybeexpectedinbothdietsandtherelativepricesoffoods.AnalysisofpricesintheUnitedKingdom(UK)hasbeenaddedtoprovidesomecomparison.TheliteraturefromtheUnitedStates(USA)hasbeenreviewedgiventhelargenumberofstudiesthatreportonthepriceoffood,theeffectonfoodconsumptionandinsomecasestheconsequencesforbodyweight.
Whilechangesinpricesofsomefoodssuchasbananas,beverages,cereals,dairyproduce,edibleoilsandsugaroninternationalandnationalmarketsareregularlyreported,
lessisknownabouttheevolutionofnationalretailpricesoffoodintheformpresentedtoconsumers.Hencethecentralquestionsposedinthisreport:
• Whatchangeshavebeenseenintheretailcostoffoodinthefourcountriessince1990?Aretheresystematicdifferencesintheevolutionofpricesfordifferentfoods,andhencechangesinrelativeprices?
• Inparticular,hasprocessedfoodbecomecheaperrelativetounprocessedstaples,fruitandvegetables,meatanddairyproduce?Thismaybeexpectedsincemuchoftheretailcostofprocessedfoodarisesinmanufacturingandlogistics,wheretechnicaladvanceshavereducedunitcosts,perhapsbymorethanadvancesinfarminghavereducedthecostofagriculturalproduce.
Itwaspossibletoexamineonlyasampleofthemanyfoodsonofferinretailoutlets,theaimbeingtohaveatleastoneexamplefromthefollowingfoodgroups:
• Staples Cereals,rootcrops,legumes • Fruitandvegetables Fruitandvegetables • Meat,fishanddairy Minimallyprocessedanimal productsandmilkproducts
• Oils,fats,andsugar Vegetableoilsandfats, animalfats,sugar
• Highlyprocessedfoods Foodsusuallyproduced byindustrialprocesses
What is already known? Insights from the literaturePublishedstudiesforthe UKandtheUSAfrequentlyreportthefollowing,evenifcontraryfindingsandqualificationscanbefoundinmanyotherstudies:
• Moststudiesfindthathealthierfoodscostmorethanlesshealthyones.Moreoverthiseffecthasincreasedoverthelast30–40years,asenergy-dense,processedfoodshavebecomecheaperrelativetolessenergy-densefruitandvegetables.
• Consequentlyhealthydietstendtocostmorethanlesshealthydiets.Thisisnotinevitablyso:choosingcheaperhealthyitemsandsubstitutingthemforcostlierlesshealthyonesmightbothimprovedietandsavemoney.Butformostconsumers,thiswouldrequireboththeabilitytoseethedistinctions,andthedisciplinetofollowaparticulardiet.
• Althoughitseemsthatsomeenergy-denseprocessedfoodshavebecomenotablycheapercomparedtofruitandvegetables,thenatureofthelatterhavechanged
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The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 9
–withhigher-valueprepareditemscommoninfoodoutlets,andalsoavailableallyearround.Takingsuchaddedvalueintoaccountthechangeinrelativepricesmaybelessthanisatfirstapparent.
• Consumptionofmostfoodsrespondstopricechanges,althoughformanyfoodstheresponseisrelativelyinelastic–butfarfromperfectlyso.Thoseonlowincomesaremostlikelytorespondtochangingprices.
Studiesoftheimpactsoffoodtaxesthatoftenseemtotriggertinychangesinconsumptionobscurethesefindings,butthisisbecausemoststudiesobserveormodeltheeffectsofverylowtaxes,5%orlessbeingtypical.
• Cross-priceeffectsmatterinassessingthenutritionaleffectsofpricechanges.Taxesonfatorsaltcontentmayaffectconsumptionofother,complementaryfoodsleadingtolessconsumptionofbeneficialnutrients.Usingtaxrevenuestosubsidisesuchcomplementaryfoodswouldcounterthiseffect.
• Studiesoftheimpactsofchangesinpricesonbodyweightproduceasurprisinglystrongconsensusthathigherpricesofunhealthyoptionsreducebodymassindex(BMI),asdocheaperhealthieroptions.‘Surprising’sincebodyweightistheoutcomeofmanyfactors,yetpriceschangescanbeseentomakeadifference.Thestrongesteffectsareseenamongthoseonlowincomeswhoaremostsensitivetothecostoffood.
Therearefewerstudiesonthefouremergingeconomies,buttheyindicatethefollowing:
• Somestudieslinkchangesindiets,aboveallthoseinvolvingmoreconsumptionofprocessedfoods,toprocessedfoodandcookingoilbecomingcheaperthanotherfoods.
• InLatinAmerica,therisingconsumptionofultra-processedfoodsandsugar-sweetenedbeverages(SSBs)isnotable.Someseethisastheconsequenceofheavymarketingbythelargecorporationsthatmanufacturemuchofthisfoodanddrink.
• ThepossibilityofusingtaxestoreduceconsumptionofprocessedfoodandSSBsisactivelybeingstudied,withmostauthorsseeingthepotentialtosignificantlyreduceconsumption.MexicohasalreadyintroducedtaxesonbothSSBsandenergy-densefood.These,whichcameintoeffectinJanuary2014,willbethefocusofintensescrutinytoseewhateffectstheyhave.
Data and methodsKeydataforthisreportareseriesforfoodpricesfrom1990torecentyearsinthefourcountriesplustheUK.Retailpricesweresoughtforrepresentativefoods–thosefrequentlyconsumed–fromthefoodgroupslistedabove.
Inmostcases,directlyobservedretailpriceswereused.ForMexico,however,afoodpriceindexwasusedandcalibratedtopricelevelsfromobservedpricesinMexico
City.IntheUK,householdsurveysreportedbothspendingandquantityfor330foods.Henceitwaspossibletocreateunitpricespaidbydividingexpenditurebythequantity.
Priceserieshavebeendeflatedbyeithertheconsumerpriceindex(CPI)ortheGrossDomesticProduct(GDP)deflatortoremovetheeffectofinflationandallowcomparisonovertime.Oncepricesweredeflated,indicesofthesesdeflatedpriceswereconstructedtoseehowmuchpricesofdifferentfoodsineachcountryhadchangedsincethesamebaseyear.
Moreformaltestingofpricechangeswascarriedoutbyregressingtimeondeflatedandloggedpricesfrom1990toarecentyear,inmostcases2012.Thisallowedatestofwhetherasignificant(log-linear)trendcanbeinferred,andifso,whattheaverageannualpricechangehasbeen.
ResultsThekeyfindingsfromtheanalysiscomefromestimatedannualpricechanges(seeFigureA).
Twothingsarereadilyapparent.Oneisthatpricesoffruitandvegetableshaverisensubstantiallysince1990,mainlybybetween2%and3%ayearonaverage–orby55–91%between1990and2012.Theotheristhatfourofthesixprocessedproductsforwhichestimatesaresignificantshowpricefallssince1990.Mostoftheotherfoodshaveseentheirpricesriseby1–2%ayear,withtheexceptionofthepricefallsforriceinKoreaandchickeninMexico.
DiscussionIfthedetectedtrendsarerealtheypromptquestionsaboutthereasonsforthem.If,forexample,technicalprogressinfarmingwereuniform,sothatunitcostsofproductionwerefallingforallagriculturaloutput,andifadvancesinthelogisticsoffoodwholesalingandretailingweresimilarlyuniform,thenwemightexpectthecostsofmostfoodstomoveroughlyinlinewithoneanother.Butthatisnotthecase.
Sowhyhavefruitandvegetablesbecomemorecostlycomparedtootheritems?Itisnotasthoughtherehavenotbeentechnicaladvancesinhorticulture:onthecontrarysomeofthemostsophisticatedseeds,soilnutrition,watercontrol,andpreventionofpestsanddiseasesareseenpreciselyinthegardensandglasshousesinwhichsomanyfruitandvegetablesaregrown.WhilethereisaworldofdifferencebetweenDutchheatedglasshousesandthetinyplotsofgreenbeansofcentralKenya,inbothcases,comparedtootheragricultureintheirneighbourhoods,thesesystemsarebothmoreintensiveandusemoresophisticatedtechnologythanmostotherlocalfarmenterprises.Moreover,advancesintransportmeanthatfruitandvegetablesaretradedmorethaninthepast,sothatretailmanagersshouldbeabletosourcefromlow-costsuppliersnomatterwheretheymaybe.
Hypothesescanbeimagined:horticulturemaywellhaveasteppedsupplyfunction,sothatwhilesmallquantitiesoffruitandvegetablescanbesuppliedatlowunitcost,onceaparticularvolumeisreached,costsrapidlyescalatetoasignificantlyhigherlevel.Itmayalsobethatthechangesinqualitynotedexplaintheincreasedrelativeprices.Or,itmaynotbeamatterofcostbutofincreaseddemandfromthoseconsumerswhoappreciatethehealthbenefitsoffruitandvegetables.Thesehypothesesmeritaseparatestudy.
Whydoesnotthesameapplytosomeprocessedfoods?Onepossibilityisthatmuchprocessedfooddoesnotrelyoncostlyfarmingredients,butratherismanufacturedfromrelativelycheapingredients,theaddedvaluebeinglargelyinfactoryprocessesofcombiningtheingredientsandenhancingtheirflavour.Advancesinmanufacturingandflavouringprobablyhelpreduceunitcostsinfactory.Thatsaid,processedfoodsarenotuniforminqualityandpricing,sinceforanysub-category,thereareusuallyproductsthatarebranded,soldontheirspecialcharacteristics,usuallywithapricepremium–asapplies,forexample,toSSBs,whichcompetewithcheaper,unbrandedoptions.Thismayexplainwhynotalltheprocessedfoodsconsideredshowdecliningconstantprices.Again,additionalstudiesmightshedlightonthis.
Evidencepresentedintheliteraturereviewsuggeststhatpricesdoaffectconsumption,especiallyforpeople
onlowincomes.Henceitisnosurprisetoseemuchstudyofthepotentialoftaxesonlesshealthyoptionstoreducetheirconsumption,perhapsevenwithsubsidiesonmorehealthyoptionstoraisetheirs.Mostsuchstudiesindicatethatimposingtaxeswouldreduceconsumption.Buttwoqualificationsapply.
Oneisthattheremaybecross-priceeffects,wherebywhentaxesraisethecostofaparticularfood,notonlydoesitsconsumptionfall,butsotoodoesthatofcomplements(foodswhicharetypicallyconsumedtogether,suchasbreadandbutter).Whenthosecomplementscontainvaluednutrientsitisthuspossiblefortaxestoreducethequalityofdiet.Intheorythisproblemcanreadilybetackledbyplacingasubsidyonthevaluedcomplementtooffsetthecross-priceeffect.Inpractice,learningwhichfoodsreallyarecomplements,towhatextent,andthendetermininganoptimallevelofsubsidy,couldleadtoathicketofregulationsthathavetobeadjustedinthelightofemergingevidence,creatinghighadministrativecostsandgivingtheimpressionthatsuchfiscalmeasuresarejusttoodifficulttocontemplate.Thequestionishowstrongcross-priceeffectsareandwhethertheymayberemediedbyothermeasurestoencouragehealthierdiets.
Theotheristheapparentlyseductiveargumentthatsmalltaxeswouldcreateonlysmalleffects:thatconsiderablechangeinconsumptionwouldrequirehigh
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Figure A: Estimated average annual price changes from 1990
-4 -3 -2 -1 0 1 2 3 4
GrainDried rice
RiceTortilla and maize flour
Vegetable oilSoy oilSugar
Meat, Poultry and its productsFishBeef
ChickenChicken
VegetablesTomatoOrange
CabbageTomato
Fresh vegetablesFresh green vegetables
Cake, biscuit and breadRamen
Sweet biscuitChocolate and snacks
Ready mealsIce cream tub/block
CHKR
BRM
XKR
BRM
XCH
KRBR
MX
UKCH
BRBR
KRM
XM
XUK
CHKR
BRM
XM
XUK
Staples
Oil and sugar
Meat, poultry, fish
Fruit & vegetables
Processed foods
Source: Table 5.1
The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 11
taxesthatwouldlookdisproportionateandunfair–say,morethantherateofvalue-addedtax(VAT)of20%intheUK.Butalogicalflawapplies.Thepolicyquestionisnotsomuch,‘howlargeataxwouldbenecessarytobringdownconsumptionoflesshealthyfoodXtorecommendedorinsignificantlevels’,but‘howmuchbenefitwouldbederivedfromimposingapoliticallyacceptabletaxonlesshealthyfoodX?’Theanswertotheformermaybeanumbersohighastobedismissedfromthedebate;buttheanswertothelattermaybeasstrikingasthatprovidedbyNnoahametal.(2009)fortheUK:thattaxesandsubsidiesoflessthan20%couldsavenofewerthan6,400prematuredeathsayearfromcoronaryheartdisease(CHD)andcancers.Theargumentabout‘smalltaxes,
smallgains’istantamounttoargumentsthatcondemndoinggoodbecauseperfectionisunattainable.
Intermsofwhatmightbetaxedandsubsidised,thisreportsuggeststhatenergy-densefoodsmightbetaxed,whilefruitandvegetables,whosepricesoftenrisecomparedtootherfoods,mightbesubsidised.
Muchcomesdowntothepoliticalappetitetocontemplatetaxingfoods.EventsinMexicosuggestthatsomeemergingeconomiesmaystealamarchonHICsinthisrespect.TheevidencepresentedinthisreportsuggeststhattheMexicantaxesshouldachieveconsiderablegood,therebyprovidingvaluablelessonsforotherdevelopingandemergingeconomies.
1. Introduction
The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 13
Box 1A: Mapping drivers of overweight and obesity: spaghetti junctions ahead
Amultitudeoffactorsinfluenceanindividual’schanceofbeingoverweightorobese.TheUKForesightstudyonobesityidentifiedbroadthematicclustersofSocialandIndividualPsychology,FoodProductionandConsumption,Physiology,IndividualPhysicalActivityandPhysicalActivityEnvironment,outlinedinthickdottedlinesontheirdiagramofinteractions(Figure1A1).
Figure 1A1: Foresight’s causal map of overweight and obesity clustered by type of driver
Source: Map 5 in Butland et al. 2007
Withineachoftheclustersmultiplefactorsinteract.Belowisthefoodconsumptionclusterwheremanyoftheeconomicfactorscomeinto,seeFigure1A2.
Figure 1A2: Extract from Foresight’s causal map of overweight and obesity
Source: Section of Map in Butland et al. 2007
Theprevalenceofpeoplewhoareoverweightandobeseisincreasingacrosstheworld,especiallysoindevelopingcountries(KeatsandWiggins2014;Ngetal.2014;PopkinandSlining2013;Stevensetal.2012).Someemergingeconomiesnowhavealmostthesameprevalenceofoverweightandobesityasseeninhigh-incomecountries(HICs).Thecostsarehigh.Notonlydoesexcessweightmakepeoplemoresusceptibletoheartdisease,somecancers,strokesandtype-2diabetes,butalsoitleadstoeconomiclossesandhighercostsofhealthcare(Gortmakeretal.2011).
Nonationhasstemmedtherisingratesofpeoplewhoareoverweightandobese.Effectivepoliciestocombatobesityhaveyettobeproved,ifonlybecausenocountryhasyettestedasufficientlycomprehensivesetofpolicies.Causesofexcessweightarewidelyagreedtobemultiple,rangingfromthesimpleeconomicsofrisingincomeandfallingcostsofmanyenergy-denseprocessedfoods,whichallowspeopletoeatmore,tomoresedentarylivesassociatedwithurbanisation,tosocio-culturaleffectsofadvertisingandmediaimages,andeventopotentialaddictiontohighlypalatablefoods(Hawkes2008;Kearney2010;Swinburnetal.2011).Oftentheproblemisseenasarisingfromsystemicchange.Asystemsmapofthedriversofoverweightandobesity,developedintheUKgovernment’sForesightprogramme(Butlandetal.2007)(seeBox1A),showsjusthowcomplex(andinterrelated)thedriversarebelievedtobe.
Thisreportaddressesonepartofthesystem:thewayinwhichpricesoffoodinfluenceschoiceofdiet.Ifdietshavetendedtoincludemoreenergy-densefoods,andespeciallyprocessedfood,isthislargelybecausethesefoodshavebecomerelativelycheapcomparedtofoodlessdensein
energyandoftenunprocessed?Theanswerhasimplicationsforpolicy:namelytheeffectivenessofusingtaxesandsubsidiestoinfluencediets,andhencepublichealth.
Tothebestofourknowledge,noexistingstudycomparesthechangingcostsoffoodsforseparatefoodgroupsacrossasampleofdevelopingandemergingeconomies.Althoughasimpleexercise,itcouldthereforebeofconsiderableinteresttoothersstudyingcausesandpotentialpolicyresponsestorisinglevelsofobesity.
Thisreportaimstounderstandbetterhowrelativepricesofdifferentfoodshavechangedsinceatleast1990,orearlierwhendatapermit,andhowthismayhaveledtodietarychanges.PlentyhasbeendocumentedaboutchangingrelativepricesoffoodsforHICs,aswillbeseenintheliteraturereviewofstudiesoffoodpricesintheUSAandtheUK.Less,however,isknownaboutchangesinpricesindevelopingcountries,aboveallinemergingeconomieswheretheprevalenceofoverweightandobesepeopleisgrowingfastest.Thisreportaimstohelpfillthisknowledgegap.Itfocusesonfourcountries:threeupper-middle-incomecountries(UMICs)–Brazil,China,andMexico–andoneHIC,theRepublicofKorea,whichwasstilladevelopingcountryin1990.Theyhavebeenchosensincetheyrepresentemergingeconomies1thataregrowingfasterthanmostoftheindustrialisedcountries,wheresince1990significantchangesmaybeexpectedinbothdietsandtherelativepricesoffoods.AnanalysisofpricesintheUKhasbeenaddedtoprovidesomecomparison.
Eachofthesefourcountrieshasseenarapidincreaseintheburdenofoverweightandobesitysincethe1980s(seeFigure1.1).AlthoughprevalenceisstillrelativelylowintheAsianexamples,ithasgrownmarkedlyfrom
1 By2015theRepublicofKoreaisnotusuallyregardedasanemergingmarket,butwasseenassuchatthestartofthestudyperiodin1990.
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Figure 1.1: Prevalence of adult overweight and obesity in four countries plus the UK and USA, 1980–2008
45%
39%36%
25%
14% 13%
23%
71%
64%68%
52%
32%25%
34%
15830 45 64 12
241
1,461
0
200
400
600
800
1000
1200
1400
1600
0%
10%
20%
30%
40%
50%
60%
70%
80%
US UK Mexico Brazil South Korea China GLOBAL
Mill
ions
of a
dults
ove
rwei
ght &
obe
se
Perc
ent o
f adu
lt po
pula
tion
1980 2008 Number overweight and obese in 2008 (M) - R axis
Source: Compiled from data in Stevens et al. 2012
Notes: China: Latest estimates for overweight and obesity in adults 20–60 years over 35% for men and over 30% for women in 2011 – see Figures 12 and
13 in Annex III.4. Rapid increases in excess weight for those under age 20 from 2008 to 2013: for girls from 4.5% to 13%, for boys from 7% to 23%. (He
2013). Mexico: between 2002 and 2012 much of the increase in people overweight and obese came from already overweight people becoming heavier.
The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 15
the1980s.Oftheselectedcountries,Chinahasseenthesmallestproportionalincreaseinoverweightandobesity,thoughthesheersizeofChina’spopulationmeanstheburdenofoverweightandobeseadults,thoughrepresentingonly25%ofthepopulation,outstripsbysome50milliontheburdenintheUKandUSA.
Themedicalcostsofexcessweightarealreadyconsiderableandrising:
• Brazil:annualcostofdiseaserelatedtoexcessweightisestimatedatUS$2.1billion,ofwhichUS$21millionisdirectlyattributabletooverweightandobesity(Bahiaetal.2012).
• China:directmedicalcostsofadultchronicdiseasesattributabletooverweightandobesitywereestimatedataroundYuan21billionin2003[US$2.74billion](Zhaoetal.2008).Economiclossesfromprematuredeathsfromheartdisease,strokes,anddiabeteswereestimatedin2005atUS$18billion(WHOFactsheetat:http://www.who.int/chp/chronic_disease_report/media/china.pdf?ua=1).
• Mexico:DiabeteshasbeenaleadingcauseofdeathinMexicosince2002,followedbycardiovasculardisease(CVD)andbraindisease.Prevalenceoftype-2diabetesinadultsisupfrom6%in2000toover9%in2012(ValdésRamos2012).
Thefourcountrieshavealsoseensignificantchangesintheirdietsforatleastthelast20years,forsimilarreasonstothoseseeninHICs:risingincomes,urbanisation,moresedentaryoccupations,changesincostsoffoodandtheinfluenceofmarketingandmediaontastes.Box1Breportsonhowwhiledietsacrosstheworldhavecometocontainmorehealthyfoods,inthefouremergingeconomiestheyhavealsotendedtoincludemoreunhealthyones.
Therestofthereportissetoutasfollows.Section2statestheresearchquestionsandobjectives,andpresentsthehypothesisedcausalchainfromfoodpricestoobesity.Section3reviewstheliteratureonfoodpricesandtheirrelationtoconsumption.ThisbeginswiththequitelargeUSliterature,reviewedbecausemoreisknownabouttheobesityintheUSAthananywhereelse.FollowingthatsomeoftheliteraturefortheUKandthefouremergingeconomiesisreviewed.Section4recordsthesourcesofdataandthemethodsusedtoanalyseit.Section5presentsthefindings.FinallySection6concludesanddiscussestheresults.
MoredetailedinformationfortheemergingeconomiescanbefoundinAppendixIII.
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Fromdetailedsurveysofdietsacrosstheworld,dietshavebeenassessedfortheextenttowhichhealthyandunhealthyfoodsareconsumed(Imamuraetal.2015).Thefoodswerecategorisedasfollows:
• Healthyitems:fruits,vegetables,beansandlegumes,nutsandseeds,wholegrains,milk,totalpolyunsaturatedfattyacids,fish,plantomega-3sanddietaryfibre.
• Unhealthyitems:unprocessedredmeats,processedmeats,sugar-sweetenedbeverages(SSBs),saturatedfat,transfat,dietarycholesterolandsodium.
Eachcountrywasgivenastandardised(1–100)scoreaccordingtointakerelativetotheglobalsample.Forunhealthyoptions,higherscoresrepresentlessconsumptionofthese.
Ofthesixcountries,dietsinMexico,theUKandBrazilcontainthemosthealthyoptions,whileChinaandKoreahavetheleast(seeFigure1B1,panelA).Thedifferences,however,arenotthatlarge.Morestrikingarethedifferencesinconsumptionofunhealthyfoods(seepanelB),whereChina,KoreaandMexicohaveleastconsumption,whileBrazilandtheUSAhavethehighest.
Figure 1B1: Average diets, six countries, 2010, standardised scores
(a) Healthy options (b)
Unhealthy options
Source: Fumiaka Imamura, personal communication
Evenmorestriking,however,arethechangesinthesescoresseensince1990(seeFigure1B2).Allcountrieshaveseenanincreaseinconsumptionofhealthyitems,exceptforChina.Forunhealthyfoods,theUKandtheUSAhaveseenlessconsumptionoftheseitems,butalltheemergingeconomieshaveseenrisingconsumptionofunhealthyfoods.
Figure 1B2: Changes in consumption of healthy and unhealthy foods, six countries, 1990–2010, changes to standardised scores
Source: Fumiaka Imamura, personal communication
Insum,itseemsthatinmostofthesixcountries,dietscontainincreasingquantitiesofhealthyitems,offsetinthefouremergingeconomiesbyincreasingquantitiesofunhealthyitems.
0
20
40
60
BRA CHN KOR MEX UK USA
0
20
40
60
80
BRA CHN KOR MEX UK USA
Box 1B: Changing diets in the four countries, UK and USA
-10 -5 0 5 10
BRA
CHN
KOR
MEX
UK
USA
Quality Change,healthy foods
Quality Change,unhealthy foods
2. Research questions and
objective
Thisreportstartsfromtwoworkinghypotheses:
a)Whentherelativepricesoffoodschange,peoplewillconsumemoreoffoodsthathavebecomerelativelylessexpensive,andlessofthosethathavebecomerelativelymoreexpensive.Peopleonlowincomesareexpectedtobemoresensitivetopricesthanthoseonhigherincomes;and,
b)Whenconsumptionoffoodswithhighcaloriecontentperunitweight(energy-densefoods)increasesattheexpenseoffoodlessdenseinenergy,thenwemayexpecttoseeasignificantincreaseintheprevalenceofoverweightandobesepeople.
ThecausalchainthatrunsfromfoodcoststoconsumptiontoobesityandillhealthissetoutinTable2.1.Thelogicrunsfromfactorsthataffectfoodprices–bothchangesincoststhataffectthemdirectlyandotherfactors–tochangesinfoodpriceswhich,togetherwithfactorssuchasincomes,leadtochangesinthepurchaseandconsumptionoffood,whichtogetherwithotherfactorssuchasphysicalactivity,leadtochangesinbodyweightthatfinallyleadtoillhealth.ThischainhasbeenusedtostructurethereviewofliteraturefortheUSA,wheresomelimitthemselvestolevel1,otherstrytoconnect1to2,orto2,3and4orgostraightfrom1to3or4.
Whilechangesinthepricesofsomefoodssuchasbananas,beverages,cereals,dairyproduce,edibleoilsandsugaroninternationalandnationalmarketsareregularlyreported,lessisknownabouttheevolutionofretailpricesinnationalmarketsforfoodintheformpresentedtoconsumers.Hencethecentralquestionsposedhereare:
• Whatchangeshavebeenseenintheretailcostoffoodinthefourcountriessince1990?Aretheresystematicdifferencesintheevolutionofpricesfordifferentfoods,andhencechangesinrelativeprices?
• Inparticular,hasprocessedfoodbecomecheaperrelativetounprocessedstaples,fruitandvegetables,meatanddairyproduce?Thismaybeexpectedsincemuchoftheretailcostofprocessedfoodarisesinmanufacturingandlogistics,wheretechnicaladvanceshavereducedunitcosts,perhapsbymorethanadvancesinfarminghavereducedthecostofagriculturalproduce.
Itwaspossibletoexamineonlyasampleofthemanyfoodsonofferinretailoutlets,theaimbeingtohaveatleastoneexamplefromthefollowingfoodgroups:
• Staples Cereals,rootcrops,legumes • Fruitandvegetables Fruitandvegetables • Meat,fishanddairy Minimallyprocessedanimal productsandmilkproducts
• Oils,fats,andsugar Vegetableoilsandfats, animalfats,sugar
• Highlyprocessedfoods Foodsusuallyproduced byindustrialprocesses
Thegroupshavebeenconstructedlargelyfortheirnutritionalcharacteristics,withstaplesbeingaprimesourceofenergy;fruitandvegetablesfortheirvitaminsandminerals;meat,fishanddairyforprotein;and,oils,fatsandsugarsforenergyinparticularlyconcentratedform.Totheseconventionalgroupshavebeenaddedhighlyprocessedfoods,thatisthosethat
Table 2.1: Causal chain from costs of food to consumption, obesity and ill health
Level Direct links Other factors
0 Increases in productivity … in• Agriculture;• Foodprocessing;and,• Foodtransport,storage,distributionandretailing… that reduce unit costs of food.
Publicpolicy:Taxes,SubsidiesPricingasmarketingstrategy–offers,lossleaders,etc.
1 Changeinfoodprices,constant,netofinflation• Absolute,comparedtoothergoodsandservices• Relative,onefoodorgroupoffoods,comparedtoanother
IncomesTransfers–foodstampsPreferences–influencedbyadvertising,publiceducation,media,peersAvailability–e.g.food‘deserts’
2 Changein(purchaseand)consumption Geneticandphysicalfactors–abilitytouseenergy,storefatPhysicalactivity–influencedbywork,transport,sportsandleisureoptions,etc.
3 Changeinweight(BMI,fatcomposition) Remedialmedicalinterventionssuchasprescribeddrugs
4 Diseaseandillheath:• Prematuredeath,disability,illness• Costsofhealthcare• Economiclosses
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The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 19
Box 2A: Energy density of foods
Foodsvaryconsiderablyintheirenergydensity,asFigure2A1forselectedsnacksintheUSAshows.
Figure 2A1: Energy density of selected healthy and less healthy snacks, USA, kcal per 100 grams
0 100 200 300 400 500 600
CeleryTomatoes, grape/cherry
Broccoli floretsWatermelonRed peppersStrawberries
CantaloupeCarrots, baby
PlumOranges, navel
ApplesTangerines
Peaches, cannedFruit cocktail, canned
Pineapple, cannedGrapes
Applesauce, jarredBananas
Sweet potatoes, cookedPudding, ready-to-eat
Ice creamPizza, from frozen
RaisinsCupcakes
DanishFruit rolls
Toaster pastriesPretzels
Granola barsMuffinsDonuts
Graham crackersCookies
CrackersSandwich crackers
Tortilla chipsCorn chips
Potato chipsChocolate candy (off scale)
Calories per 100g
1008
125kcal/100g - WCRF average dietary density recommendation
275kcal/100g - Mexican energy-dense tax threshold
Source: Constructed with data from USDA (thresholds added)
Foodsinlowinenergyforweightareseenasbeingpartofahealthydiet.TheBritishNutritionFoundationclassifiesfoodbyenergydensityasfollows:
• Verylow <60kcalper100grams • Low 60to150kcalper100grams • Medium 150to400kcalper100grams • High >400kcalper100grams
Source: http://www.nutrition.org.uk/healthyliving/fuller/what-is-energy-density.htmls
TheWorldCancerResearchFund(WCRF)recommendsdietsinwhichmostitemscontainlessthan125kcalper100grams.Mexicodiscouragesconsumptionoffoodswithmorethan275kcalper100gramsthroughtheimpositionofatax
(seesection3.6).Energydensityisjustonedimensionofahealthydiet.TheImamuraetal.(2015)studyoutlinedinBox1Breflects
amedicalconsensusontenhealthyfoodsorcategoriesandtenunhealthyoptions(thestudywasabletomeasureonlysevenoftheten).
Locketal.(2010)summariseaconsensusonhealthydietsasfollows:
• Asystematicreviewofdietaryrecommendationsdefinedbyexpertpanelsandpublishedbetween1990and2004forthepreventionofnutritionaldeficienciesandinfectiousandchronicdiseases,identifiedabroadconsensusacross94reports.Consensualexpertopinionsuggeststhathealthydietsshouldcontainlargeamountsofcereals,vegetables,fruits,andpulses,whilelimitingtheamountofredandprocessedmeat,resultinginahighintakeofdietaryfibreandmicronutrientsandalowintakeoffats,saturatedfattyacids,addedsugars,andsalt.(WCRF2007)
• Inadditiontomaintenanceofenergybalance(totalcaloricintakevstotalenergyexpenditure)andhealthyweight,ahealthydiettoprovideadequatepopulationnutritionandreducechronicdiseaseriskconsistsof:15–30%oftotalenergyasfat,ofwhichsaturatedfatshouldbelessthan10%andtransfattyacidslessthan1%;55–75%oftotalenergyastotalcarbohydrate,ofwhichaddedsugarsshouldbelessthan10%;10–15%oftotalenergyasproteinfrommainlyplantsources;lessthan5gperdayofsalt;andmorethan400gperdayoffruitsandvegetables.(WHO/FAO2003)
havebeenproducedindustrially,oftenaddingtothemainingredientsadditionalfatoroil,salt,sugarandflavouringstoenhancetasteandpalatability.
Threeofthesefoodgroupsareofparticularinterestfortheirpotentialroleindietsthatleadtoobesity.Foodsthataretypicallydenseinenergy(seeBox2A)makeitpossibletoeatlargeamountsofcaloriesbeforefeelingfull.Theyincludethetwocategoriesoffats,oilsandsugar;andhighlyprocessedfoods.Fruitandvegetablesconstitutetheothergroup,partlybecausemostarenotdenseinenergy,andpartlybecauseitiswidelyconsideredthatdietsinHICsshouldincludemoreoftheseitems(see,forexample,USDA2015).Ifitwerethecasethatpricesofoils,fats,sugarsandprocessedfoodswerefallingrelativetofruitandvegetables,thiswouldbeacauseforconcernsinceitwouldbeaneconomicencouragementtoselectlesshealthyitemsindiets.
Additionalanalysiswouldbenecessarytotracetheseeffectsalongthecausalchain.Forthetimebeing,theaimiskeptsimpleandstraightforward:torecordchangesinthepricesoffoodsfromdifferentcategories.Insubsequentresearchwehopetofollowupthisquestionbyaddressingtheprobableconsequencesofchangesinrelativepricesoffoods,asking:
• Dochangesintherelativepricesoffoodcorrelatewithchanginglevelsofconsumptionofthemainfoodgroups?
• Dotheycorrelatewithchanginglevelsofoverweightandobesity?
• Whereenergy-densefoodshavebecomerelativelycheaperthanotherfoods,havetherebeenmorerapidincreasesinlevelsofoverweightandobesity?
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3. What is already known?
3.1 United States
3.1.1 Background: the high rates of overweight and obese people in the USA
OverweightandobesityratesintheUSAareamongthehighestintheworld,andthehighestamongOECDcountries(seeFigure3.1).Some74%ofUSadultmaleswereestimatedtobeoverweightorobesein2008,afigureexceededonlybyratesineightsmallPacificislandnations2andKuwait.USadultfemaleshadslightlylowerestimatedratesofoverweightandobesity,some68%in2008,3althoughstillextremelyhigh.
In2008,thedirectmedicalcostofoverweightandobesityintheUSAwasestimatedatUS$113.9billion,about0.77%ofUSGDPthatyearaccordingtoWorldBankdata(Tsaietal.2011).4
ObesityhasbeenrisingintheUSA:
Inspiteofincreasedrecognitionandmediaattentiontotheproblem,theobesityepidemiccontinuestoworsen.Justbetween2000and2005,theprevalenceofobesityintheUSAincreasedby24%,whilethenumberofseverelyobese[bodymassindex(BMI)>40]cases
increasedby50%,high-lightingtheimportanceofchangeovertime.Whenlookingattrenddata,changesinBMIappeartobeverysimilaracrossallpopulationgroups,althoughtheprevalenceatanypointishighestamonggroupswithlowerincomeandeducation,andsomeethnicminorities.(Sturm2008)
Whileobesityisanindividualcondition,itswidespreadprevalenceandincreasesuggestthatthedriversmustincludefactorsthataffectmanypeople,notjustindividuals.
USdietsarefarfromthenutritionist’sideaofwellbalanced.Theycontaintoomuchoil,protein-richfood,cerealsandsugar,andtoofewfruitsandvegetables.
Tomeet2005Dietary Guidelines,typicalAmericanswouldneedtomorethandoubletheircurrentintakeofvegetablesandwhole-grainfoodswhilereducingtheirintakeofsolidfatsandaddedsugarsbyhalf(U.S.DepartmentofHealthandHumanServicesandU.S.DepartmentofAgriculture,2005).(KuchlerandStewart2008)
Thirtyyearsago,dietswerenotquitesounhealthy:calorieavailabilityintheUSAhasrisenmarkedlysincethe1970s.Sturm(2008)reportsthattheincreaseinavailableenergycomesalmostentirelyfromcarbohydrates,especiallySSBsandsnackfoods:
Theavailabilityofsugar-sweetenedbeveragesandsnackitemshasincreasedparticularlyquickly.Between1970and2005,caloricsweetenersincreasedby20poundspercapitaperyear;sweetsandconfectionarygoodsincreasedby3pounds…Theavailabilityofsugar-sweetenedbeveragesincreasedby8.5gallonspercapitaperyearfrom1985to2005;40%ofthisincreasewasduetofruit-flavoreddrinksandsportsdrinks,andtheremainderwasduetocarbonatedsoftdrinks.
Sturmconsiderstheseincreasestobemorethanenoughtoexplaintheepidemicofobesity,evenwhenconsideringwaste.
Overthe40yearsfrom1970to2009,totalenergyavailabilityincreasedalmost11%percapita,accordingtoCardenandCarr(2013).Energyfromprotein,carbohydratesandfatincreasedbyaround5%,10%and15%respectively.5
2 Nauru,CookIslands,Tonga,FrenchPolynesia,Samoa,Palau,Kuwait,KiribatiandtheMarshallIslands(datafromStevensetal.2012).
3 OnthisindicatortheUSAlagsbehindsomeothercountriesinprevalence(thosealreadymentionedforthecaseofmen,aswellastheFederatedStatesofMicronesia,SaintKittsandNevis,PuertoRico,NetherlandsAntilles,Egypt,Belize,Barbados,SouthAfrica,Fiji,UAE,Bahrain,Dominica,Bahamas,Qatar,SolomonIslands,MexicoandSaudiArabia)(datafromStevensetal.2012).
4 Bywayofcomparison,theUSAspentaroundUS$49.1billiononforeignaidin2008.
5 Theybelievethattoomuchemphasisisplacedontheincreasedintakeoffructoseforwhichtheyseetheyseenoincreasefrom1970to2009:increasesinglucoseandfatwerethemaincontributors.
Figure 3.1: Prevalence of overweight and obesity, USA, by age and sex, 2011–12
Source: Compiled from data from Tables 3 and 4 in Ogden et al. 2014
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The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 23
StudiesoffoodpricesintheUSAtypicallyposethefollowingquestions:
• Arehealthierfoodsmorecostlythanlesshealthyfoods? • Howhavethepricesofdifferentfoodschangedovertimerelativetooneanother?
• Howdoesconsumptionrespondtopricechanges–includingthoseinducedbytaxesandsubsidies?
• Whateffectdopricechangeshaveonlevelsofobesityandassociatedillhealth?
3.1.2 Costs of food: healthy and less healthy foods compared
Acommonwaytodefinethehealthinessoffoodsisbyreferencetoenergydensity,sinceitisassumedthatadietofenergy-densefoodswillleadtoover-consumptionbeforetheappetiteissated.Studiescomparingthecostpercalorieacrossfoodsusuallyshowthatthosedenseinenergyhavethelowestcostspercalorie.
Forexample,when372foodsinSeattlein2006weremeasuredforpriceandenergycontent,aclearinverserelationbetweenenergydensityandcostperunitofenergycouldbeseen(seeFigure3.2)(MonsivaisandDrewnowski2007).Whenfoods,otherthanbeverages,weresortedintofivequintilesbytheirenergydensity,theaveragecostper1,000kcalvariedfromUS$1.76forthemostenergy-densefoodtoUS$18.16fortheleast.
PlottingthecostsofdifferentsnackfoodsintheUSAagainsttheirenergydensityshowsasimilarpattern(seeFigure3.3).Fruitandvegetablesarenotablymorecostlypercaloriethanmostprocessedsnacks.
Connelletal.(2012)confirm,drawingondatafromtheLowerMississippidelta,thatfats,oilsandsweetsaremuchcheaperpercaloriecomparedtofruitandvegetables.
Unusually,DavisandCarlson(2012)suggestthattherelationshipbetweenpricepercalorieandenergydensityisaspuriouscorrelation,usingasampleofover4,000differentfoods,althoughencompassingfewerfoodgroupsthanMonsivaisandDrewnowski(2007)–forinstance,excludingoils,from2003/04.Aregressionofenergydensityonprice,however,forthedatatheypresentinTable1,givesanR-squareof0.41(withhighlysignificantF-statistic).
Otherstudieshaveassessedfoodsforawiderrangeofhealthycharacteristics.Forexample,Drewnowski(2010)foundthatcarbohydrates,sugarandfathadlowerpricepergram,whileprotein,fibre,vitaminsandmineralshadhigherpricespergram.
CarlsonandFrazão(2012)definedlesshealthyfoodsasthosehighinsaturatedfat,addedsugarand/orsodium,orthatcontributelittletomeetingdietaryrecommendations.Againtheyconfirmedthathealthyfoodscostmorethanlesshealthyfoodswhenmeasuredintermsofthepriceoffoodenergy.
Giventheevidencethathealthierfoodscostmorethanlesshealthyfoods,itisnosurprisethatstudies report that healthier diets cost more than less healthy ones.Forexample,peopleinthePugetSoundregionwhoeatmorevitamins,minerals,andfibrehavedietsthatcostmore(Aggarwaletal.2012).Higherintakesofdietaryfibre,vitaminsA,C,D,E,andB12,betacarotene,folate,iron,calcium,potassium,andmagnesiumwereassociatedwithhigherdietcosts–especiallysowhenthemainsourceofthenutrientcamefromfruitandvegetables.Conversely,higherintakesofsaturatedfats,transfatsandaddedsugarswereassociatedwithlowerdietcosts.Figure 3.2: Relationship between cost of per unit of
energy and energy density for 372 foods in Seattle area supermarkets, 2006
Source: Figure 2 in Monsivais and Drewnowski 2007
Note: Linear regression gives R2= 0.38.
Figure 3.3: Energy density and price per calorie for selected snack foods, fruit and vegetables, USA, 2008
Source: Constructed with data from USDA ERS database available
at http://www.ers.usda.gov/data-products/fruit-and-vegetable-prices.
aspx#.UuphpLS7Tm4
Note: Horizontal axis is a log scale.
Basedoncurrenteatinghabits,compliancewithdietaryguidelinesislikelytoentailhigherdietcostsfortheconsumer.(Drewnowski2010)
Womenwithhigh-nutrientdietswerefoundtohavemorecostlydietsonaveragethanmenwithhigh-nutrientdiets,reflectingwomen’srelativelyhigherconsumptionoffruitandvegetables,andmen’srelativelyhigherconsumptionofmeats.
Ifhealthierdietscostmorethanlesshealthyones,thenthoseonlowincomes,beingsensitivetofoodprices,arelikelytochooselesshealthyoptions.Forthoseonverylowincomes,healthydietssimplybecomeunaffordable.
Thefactthatenergy-densefoods(megajoules/kilogram)costlesspermegajoulethandonutrient-densefoodsmeansthatenergy-densedietsarenotonlycheaperbutmaybepreferentiallyselectedbythelower-incomeconsumer.Inotherwords,thelowcostofdietaryenergy(dollars/megajoule),ratherthanspecificfood,beverage,ormacronutrientchoices,maybethemainpredictorofpopulationweightgain.(Drewnowski2007)
Not all studies find that healthier diets are more expensive.Forexample,DrewnowskiandEichelsdoerfer(2009)lookedatwhetheraMediterraneandiet–consideredtoberelativelyhealthysinceitisrichinvegetables,fruits,beans,wholegrains,oliveoilandfish–costmorethanpeople’scurrentdiets.Whiletheirfindingssuggestedsomenutrient-richlow-energy-densityfoodsassociatedwiththeMediterraneandietwereexpensive,othersthatalsofitwithintheMediterraneandietarypatternwerenot.
WhenBernsteinetal.(2010)studiedthedietsofUSnursesgradedbytheAlternativeHealthyEatingIndex(AHEI),whichhasbeenlinkedtolowerratesofcardiovasculardisease,theyfoundthatsignificantincreasesinhealthinessindicescouldbeobtainedfromspendingmoreonnuts,soyandbeans,andwholegrains,whilereducingspendingonredandprocessedmeats.Insimilarvein,DrewnowskiandRehm(2013)reportthatschoolmealscanbemademorenutritious,aboveallinpotassiumandfibre,byincludingmorepotatoandbeans.
3.1.3 Changes in prices over timeThekeyissuesarechangesinpricesofdifferentfoodsrelativetooneanother.Several studies show that energy-dense food has become cheaper over time, compared to foods less dense in energy.Forexample,Gelbachetal.(2009)examinedtrendsin‘healthy’foods–freshfruitandvegetables,sodacrackers,wholemilk,lighttunaandyoghurt–comparedto‘unhealthy’foods–processedcheese,butter,cola,margarine,potatocrisps,etc.–from1982to1995.Theyfoundpricesoftheunhealthyfoodsfellfartherthanthoseforhealthyfoods.Similarly,WendtandTodd(2011)foundrisingrealpricesforfruitandvegetables,andfallingrealpricesforcarbonateddrinksfrom1980to2010(seeFigure3.4).
ThestudybyPowelletal.(2013)confirmsthesetrends:‘between1980and2011itbecame2.2timesmoreexpensivetopurchasefreshfruitsandvegetablescomparedtopurchasingcarbonatedbeverages’.Overthetwoyearsfrom2004to2006pricesofpricesofthehighestquintileofenergy-densefoodsinSeattledroppedby1.8%,whilepricesoftheleastenergy-densefoodsgrewby19.5%(MonsivaisandDrewnowski2007).
Changes in quality, seasonality and processing qualify these findings.KuchlerandStewart(2008)studiedmonthlypricesfromthe1980stothemid-2000sinUScities.Theycomparedchangesinpricesforfourprocessedfoodstopricesfor11fruitsandvegetables(seeFigure3.5).
Inseveralcases,littledifferencewasseeninpricechangesoffoodsinthetwogroups,althoughtheirattentionwasdrawntotomatoesandbroccoli,whichhadriseninpricewhilethepricesofotherfruitandvegetablesandtheprocessedfoodshadfallen.
Thismight,however,beexplainedbythreechangesinquality.One,somevarietiesofproducehavechangedovertime.Tomatoes,forexample,areincreasinglymarketedasvinetomatoesandotherspecialisttomatoes,whicharesoldatpremiumprices:theaveragetomatopriceovertimewillthusbebiasedupwards.Two,whileinthepastsomefruitandvegetableswereonlyavailableseasonally,bythemid-2000smostwereontheshelvesalltheyearround.The1980averageannualpriceofstrawberrieswasbasedonproductionduringnomorethanfourmonthsoftheUSseason:by2006theaverageyear-roundpriceincludedoff-seasonfruitproducedathighercostorair-freightedtotheUSA,withadditionaltransportcosts.Three,somevegetableswereincreasinglysoldwashed,cutandbagged,asinthecaseofbroccoli,withhighervalueaddedfortheconsumer.
Figure 3.4: Price indices for selected foods and beverages in the USA, 1980–2010
Source: Figure 1 in Wendt and Todd 2011 (based on data from the
Bureau of Labor Statistics). Note: Prices are annual average for urban
consumers. ‘All fruits and vegetables’ include fresh, canned, and
frozen. Base period 1982-84=100.
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The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 25
…valueaddedthroughtransportation,processing,wholesaling,andretailinghasgrowntoaccountforaboutthree-fourthsoftheretailpriceoffruitsandvegetables,onaverage,comparedwithabouttwo-thirdsintheearly1980s(Stewart,2006).Theseservicesservetwopurposes:increasedconvenienceandvariety.(KuchlerandStewart2008)
3.1.4 Price changes and consumption
Themostfamiliarstudiesdealingwiththeeffectofpricesonconsumptionlookatown-priceandcross-priceelasticityofdemand.Andreyevaetal.(2010)reviewedUSliteratureonhowpricechangesaffectdemandformajorfoodcategories,lookingatatotalofsome160studiesofpriceelasticityformajorfoodcategories,publishedbetween1938and2007,mostlyinthelatterpartofthisperiod.Theyfoundown-priceelasticitiesforfoodsandnon-alcoholicbeveragesrangedfrom0.27to0.81(absolutevalues),whichisrelativelyinelastic(see
Table3.1).Foodawayfromhome,softdrinks,juice,andmeatsweremostresponsivetopricechanges(0.7–0.8).
Powelletal.(2013)extendtheperiodbyreviewingstudiesofpriceelasticityfrom2007to2012(seeTable3.2).Althoughmostfoodshaveinelasticown-priceelasticityofdemand,demandforSSBsisrelativelyelastic.
Morespecificstudiesofpricelookatpriceresponse,butinthecontextofotherfactorsaffectingconsumption,andsomedifferentiatebyeconomicandsocialstatusofdifferentgroupsofconsumers:
• Powelletal.(2009a)estimatedthelinkbetweenyoungadults’consumptionoffruitandvegetablesandthepricesofthosefruitandvegetables,pricesofotherfoodconsumedathome,andfastfood,aswellastheavailabilityofrestaurantsandfoodshops.Higherconsumptionoffruitandvegetableswasassociatedwithlowerfruitandvegetableprices,withapriceelasticityof−0.32.Thisown-priceeffectwasrobusttotheinclusionofotherfoodpricesandtheavailabilityoffoodoutlets.
Figure 3.5: Long-term average annual changes in retail prices for selected foods in the USA
Source: Tables 3 and 4 in Kuchler and Stewart 2008 (based on ERS calculations using Bureau of Labor Statistics), US City average price data
and urban CPI.
Note: suspended series are those with prices not recorded between 2000 and 2006 (by 2000 bagged versions and prepared salads accounted for
large share of produce sold).
Youngadultswithlowerincomesandlowerlevelsofeducation,thosewithlowereducatedmothers,andmiddle-incomeparentswerethemostpricesensitive.Theyfoundnostatisticallysignificantcross-priceeffectsonfruitandvegetableconsumptionfromothergroceryprices(meat,dairyandbread)orfastfoodprices.
• PowellandHan(2011)sawsomepriceresponseamongadolescentstothecostoffastfoods,butonlyamongthoseonlowincomes.
• French(2005)lookedathoweffectiveprice-basedinterventionsmightbetopromoteconsumptionofhealthierfoodsinworkplacesandschools.Reviewingseveralstudies,shefoundpricereductionsoflower-fatsnackoptionsof10%,25%and50%ledsalesofthesesnackstoincreaseby9%,39%and93%respectively.Salesoffreshfruitandvegetablesalsoincreasedwhentheirpriceswerehalved.
• Khanetal.(2012)reportedthata10%increaseinthepriceoffastfoodwasassociatedwith5.7%lowerfrequencyofweeklyconsumptionoffastfoodamongchildreningrades5and8.
• SturmandDatar(2011)examinedthevaryingpricesoffoodsacrossUSmetropolitanareas.Amongchildreningrade5(averageageof11),theyfoundlowerrealpricesforvegetablesandfruitspredictsignificantlyhigherfrequencyofintake.Higherdairypricespredictlower
frequencyofmilkconsumption,whilehighermeatpricespredictincreasedmilkconsumption.Similarpriceeffectswerenotfoundforfastfoodorsoftdrinkconsumption.
• Powelletal.(2013)showedcleartrendstowardsincreasedintakesofSSBsandfoodeatenawayfromhome(particularlyfastfood),forwhichpriceshadfallen;andlowandlittle-changingconsumptionoffruitandvegetablesforwhichpriceshadrisenoverthelasttwodecades.TheyalsosawstrongereffectsonthoseonlowincomesandontheSupplementalNutritionalAssistanceProgram(SNAP)thatistheUSA’sbiggestnationalfood-stampwelfareprogrammeforthoseonlowincomesand/orunabletowork.
Table 3.1: US own-price elasticity of demand, by food and beverage category, 1938–2007
Food and Beverage Category (a) Absolute Value of Mean Price Elasticity Estimate (95% CI) Range No. of Estimates
Foodawayfromhome 0.81 (0.56,1.07) 0.23-1.76 13
Softdrinks 0.79 (0.33,1.24) 0.13-3.18 14
Juice 0.76 (0.55,0.98) 0.33-1.77 14
Beef 0.75 (0.67,0.83) 0.29-1.42 51
Pork 0.72 (0.66,0.78) 0.17-1.23 49
Fruit 0.70 (0.41,0.98) 0.16-3.02 20
Poultry 0.68 (0.44,0.92) 0.16-2.72 23
Dairy 0.65 (0.46,0.84) 0.19-1.16 13
Cereals 0.60 (0.43,0.77) 0.07-1.67 24
Milk 0.59 (0.40,0.79) 0.02-1.68 26
Vegetables 0.58 (0.44,0.71) 0.21-1.11 20
Fish 0.50 (0.30,0.69) 0.05-1.41 18
Fats/oils 0.48 (0.29,0.66) 0.14-1.00 13
Cheese 0.44 (0.25,0.63) 0.01-1.95 20
Sweets/sugars 0.34 (0.14,0.53) 0.05-1.00 13
Eggs 0.27 (0.08,0.45) 0.06-1.28 14
Source: Table 1 in Andreyeva et al..2010
Note. Values were calculated based on the 160 studies reviewed. Absolute values of elasticity estimates are reported: the estimated elasticities
are all negative in that quantity demanded falls with rising prices. The price elasticity of demand measures the percentage change in purchased
quantity or demand with a 1% change in price. aIncluding restaurant meals and fast food.
Table 3.2: Own-price elasticity of demand for four food groups in the USA, 2007–12
Food item Price elasticity of demand Range
Sugar-sweetenedbeverages -1.21 -0.71to-3.87
Fastfood -0.52 -0.47to-0.57
Fruits -0.49 -0.26to-0.81
Vegetables -0.48 -0.26to-0.72
Source: Data from Table 2 in Powell et al. 2013
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Severalofthesestudiesweremotivatedbyaninterestinthepotentialeffectsoftaxesandsubsidiesondifferentfoods.Inasynthesisof24studiesfocusingonadolescentsaged12to17andadultsaged18andoverpredominantlyintheUSA6,An(2013)broughttogetherevidencefrom20distinctfieldinterventions–pricediscountsorvouchersforhealthierfoods:fruits,vegetables,orlow-fatsnackssoldinsupermarkets,cafeterias,vendingmachines,farmers’markets,orrestaurants–toassesstheeffectivenessofsubsidiesonpromotinghealthierfoodpurchasesandconsumption.Inallcasesbutone,subsidiesonhealthierfoodssignificantlyincreasedtheirpurchaseandconsumption.Theonenullfindingwasowingtoitssmallfinancialincentive(50centstowardsthepurchaseofanyfruitorvegetable).
3.1.5 Food prices and body weightSeveralstudieslookattheimpactofdifferentpricingonconsumptionandlinkittoweightoutcomes.Most report that higher prices for unhealthy, and lower prices for healthy options, lead to lower body weights.
Forexample,inalongitudinalstudy(WendtandTodd2011)followedanationallyrepresentativecohortofkindergartenchildrenenteringin1998/99tograde8(2007)todeterminetheinfluenceofchangingpricesofcertainfoodsonchildren’sBMIs.Theevolutionofrelativepricestheytrackedshowedpricesofwholemilk,non-alcoholicbeverages,andcarbonateddrinksfallinginrealtermsoverthelast30years,whilepricesoffruitandvegetablesroseconsiderably.Moreover,withunhealthyoptionsbecomingcheaper,consumptionrose.Theyfound:
• A10%decreaseinthepriceoflow-fatmilkinthepreviousquarterwasassociatedwithadecreaseinBMIof0.35%,.
• A10%decreaseinthepriceofdarkgreenvegetables–spinach,broccoli–inthepreviousquarterwasassociatedwithadecreaseinBMIof0.28%.
• A10%increaseinthepriceofcarbonatedbeverages(oneyearprior)wasassociatedwithadeclineinBMIof0.42%,withastrongereffectonchildreninlow-incomehouseholds.
• A10%priceincreaseinfruitjuices(100%juice)orstarchyvegetables–potato,maize–(alsooneyearprior)decreasedBMIby0.3%.
• AdecreaseinthepriceofsweetsnacksinthepreviousquarterincreasedBMIby0.27%,althoughsometimesobservedchangesweremoredelayed.
Powelletal.(2007)reportthepricesoffastfoodtobeimportantdeterminantsofadolescents’bodyweightandeatinghabits:a10%increaseinthepriceofafastfoodmealleadingtoa3%increaseintheprobabilityoffrequentfruitandvegetableconsumption,a0.4%decreaseinBMI,
anda5.9%decreaseinprobabilityofoverweight.Pricesoffruitandvegetables,aswellasdensityofrestaurantoutlets,weredeemedlessimportantdeterminants.Nonetheless,changesinallobservedeconomicandsocio-demographiccharacteristicstogetheronlyexplainedroughly25%ofthechangeinmeanBMIand20%ofthechangeinoverweightbetween1997and2003.
Duffeyetal.(2009)sawthatfromthemid-1980stothemid-2000sthepricesofsoda(SSB)andpizzafellwhilemilkpricesrose.Theyfoundthata10%riseinthepriceofsodaorpizzawaslinkedtoa7.12%or11.5%decreaseinenergyintakefromthesefoodsrespectively.Priceincreasesinbothfoodsreducedbodyweightandsusceptibilitytodiabetes.
Morrisseyetal.(2014)foundthatforunder-fivesinlow-incomehouseholds,morecostlyfruitandvegetableswerelinkedtohigherBMIsamongchildren,arelationshipdrivenbypricesoffreshfruitandvegetablesratherthanoffrozenorcannedoptions.Higherpricesforsoftdrinkswerealsolinkedtoalowerlikelihoodofthechildrenbeingoverweight.Counter-intuitively,however,higherfast-foodpriceswerelinkedtoagreaterlikelihoodofchildrenbeingoverweight.
Lookingatapopulationofadultsofover60yearsofage,Goldmanetal.(2011)founda10%dropinpricepercaloriewasassociatedwithaBMIincreaseofapproximately0.26units,ora0.77%risewithintwoyears.ThiseffectoffoodpricesonBMIwasstatisticallysimilaracrossobeseandnon-obesepopulations,whilenosignificantdifferencewasestablishedacrosspoorandnon-poorpopulations.
Althoughtheshort-termeffectofpricepercalorieonBMIappearsrelativelysmall,thelong-termeffectmaybelarger.Aftertenyears,apermanent10%reductioninpricepercalorieislinkedtoBMIincreasingby1.05units(2.5%).Overthefullspanofthestudy,thisequatestoariseinBMIof2.2units,or5.1%:asignificantcontributiontototalgrowthofmeanBMIovertheperiod(Goldmanetal.2011).
Inastudyunusualforitsinclusionofmeasuresofthepercentageofbodyfat(PBF)aswellasBMI,Grossmanetal.(2013)lookedattheinfluenceoffoodpricesonclinicalobesity–measuredbyBMIandPBF.Controllingforcontextualvariables,suchasethnicity,age,familyincome,householdtypeandsize,andeducation,theyfoundthatincreasesinrealfoodprices(percalorie)–forhomeconsumption,andintherealpriceoffast-food–ledtolowerobesityinyouthsaged12to18years,whileincreasesinrealpricesoffruitandvegetablesledtohigherobesity.
Percentagebodyfat(PBF)measureswerenolesssensitive–andinsomecasesmoresensitivetosuchpricechangesthanBMImeasures.PricesoffruitandvegetablesweremoreimportantindeterminingfemalePBFthanmalePBF.A10%riseinfruitandvegetablepricescausesPBFrisesof9%forfemalesand7%formales(significantonlyforfemales).On
6 Whilethisstudyassessesinterventionsinsevencountries,mostofthemareintheUSA(14),withoneeachinFrance,Germany,theNetherlands,SouthAfricaandtheUK.
theotherhand,thepriceofacalorieinfoodconsumedathomeorinfast-foodrestaurantsplaysamoreimportantroleinmalethaninfemalePBF(Goldmanetal.2011).
Powell(2009)andPowelletal.(2010)lookedatpricesaswelltheavailabilityoffast-foodoutlets.7Theyfoundthatthepriceoffastfood,butnotavailabilityoffast-foodrestaurants,hadasignificantinfluenceonBMIamongteenagers,withpriceelasticityof−0.08(comparedwiththepriceelasticityof−0.10estimatedusingacross-sectionalmodel).Theweightofteenagersinlowertomiddle-socio-economicstatusfamilieswasmostsensitivetofast-foodprices.
Asisterstudy(PowellandBao2009)foundfruitandvegetablepricesalmostequallystronglylinkedtochildren’sBMI:a10%increaseinthepriceoffruitandvegetableswaslinkedtoa0.7%increaseinchildren’sBMI.Theinfluenceoffast-foodpriceswasnotstatisticallysignificantinthefullsample,butweaklynegativelyassociatedwithBMIamongadolescents,withanestimatedelasticityof-0.12.Moreover,associationsoffruitandvegetableandfast-foodpriceswithBMIweresignificantlystronger(economicallyandstatistically)amongchildrenfromlow-incomehouseholds.Estimatedfruitandvegetableandfast-foodpriceelasticitieswere0.14and-0.26,respectively,amonglow-incomechildrenand0.09and-0.13,respectively,amongchildrenwithlesseducatedmothers.
SturmandDatar(2005)alsoconsideredfoodpricesandfood-outletdensityinexaminingchangesintheBMIofUSprimaryschoolchildren.LowerrealpricesforfruitandvegetablespredictedasignificantlysmallergaininBMIbetweenkindergartenandgrade3,halfofitoccurringbetweengradeskindergartenandgrade1.LowermeatpricesraisedBMI,thoughgenerallybyasmallermagnitude,whiletheeffectwasnotsignificantforBMIgainoverthreeyears.Effectsweremeaningfullylargerforchildrenlivinginpoverty,childrenalreadyatriskofbeingoverweightoralreadyoverweightinkindergarten,andAsianandHispanicchildren.Nosignificanteffectsfordairyorfast-foodpriceswerefound.
Beydounetal.(2011)lookedatwhatinfluencepriceindicesoffastfoodsandthoseforfruitandvegetableshadondietaryintakeandtheBMIofUSchildrenandadolescentsagedtwoto18years.Amongtwotonine-year-olds,ahigherfast-foodpriceindex(byUS$1)wasassociatedwithlowerfast-foodconsumption,healthiereatingpatterns,andhigherintakeoffibre,calcium,dairy,andfruitandvegetables.ThefruitandvegetablepriceindexwasrelatedtolowerfibreintakeandhigherBMIs.Theirfindingsfor10to18-year-oldswerelessconsistent.Significantassociationswerealmostequallybalancedbetweenlow-andhigh-incomegroups,withsomesignificantinteractionsbetween
foodpricesandfamilyincomeobserved,particularlyamongtheyoungergroupofchildren.
Chouetal.(2004)foundthata10%increaseinpricesatfast-foodrestaurantswouldreducetheprobabilityofobesityby0.65%,whilea10%increaseinpricesatfull-servicerestaurantswouldreducetheprobabilityofobesityby0.67%,anda10%increaseinthepriceoffoodathomewouldreducetheprobabilityofobesityby0.62%.
Powelletal.(2013)observedhigherfast-foodpriceswereassociatedwithlowerweight,particularlyamongadolescents.Lowerfruitandvegetablepricesweregenerallyfoundtolinktolighterbodyweightsamonglow-incomechildrenandadults.Theyconclude:
Thegrowingevidencebaseassessedhereinindicatesthatchangesintherelativepricesoflesshealthyandhealthierfoodsandbeveragescansignificantlychangeconsumptionpatternsand,mayhavesignificantimpactsonweightoutcomesatthepopulationlevel,particularlyamongpopulationsmostatriskforobesityanditsconsequences.Raisingthepricesoflesshealthyoptionsbytaxingthemhastheaddedbenefitofgeneratingconsiderablerevenuesthatcanbeusedtosupportcostlyprogramsandotherinterventionsaimedatimprovingdiets,increasingactivity,andreducingobesity,includingsubsidiesforhealthierfoodsandbeverages.(Powelletal.2013)
Other studies have found insignificant or negligible impacts of relative prices on body weights. ThestudybyGelbachetal.(2009)foundthatpricesofunhealthyfoodsfellfrom1982to1995morethanthepricesofhealthyfoods,butthatalthoughchangesinBMIwerecausallyrelatedtorelativefoodprices,thedegreeofinfluencewassmall.A100%taxon‘unhealthy’foodswouldreduceaverageBMIbylessthan1%andreduceincidenceofoverweightby2%andobesityby1%.
OtherstudieshavenotbeenabletofindasignificantinfluenceofrelativefoodpricesonBMIs.HanandPowell(2011),inalongitudinalstudyofover10,000youngadults,wereunabletofindasignificanteffectoffoodpricesontheprevalenceofobesityamongyoungwomen.Foryoungmen,a10%increaseinthepriceoffastfoodwaslinkedtoa13%dropinthechanceofbeingobese–althoughthisfindinglostitseconomicandstatisticalsignificancewhenindividualfixedeffects(e.g.work,maritalstatus,andschoolenrolment)wereintroduced.
Whilefoodeatenawayfromhomeneednotbeunhealthy,datasuggestthateatingonemealaweekawayfromhomefortheaverageUSconsumerleavesthemroughlytwopounds(approximately1kilogram)heaviereachyear(Toddetal.2010).TheshareofUSfoodspendingoutsidethehomehasrisentoalmost50%,comparedwith25%in1960(Kumcu2011).
7 Low-tomiddle-incomeareashave1.25–1.3timesasmanyfast-foodrestaurantsashigh-incomeareas.Theproportionoffast-foodrestaurantscomparedtothetotalnumberofrestaurantsintheUSAwentfrom17%in1997to30%in2006.Fast-foodrestaurantsandconveniencestoresarereadilyavailablearoundUSsecondaryschools,especiallythoseinlargercitiesand/orlow-incomeneighbourhoods.
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3.1.6 Effects of taxes and subsidies on consumption and body weight
Taxesandsubsidiesonfoodanddrinkseekexplicitlytochangepricesandtherebytoinfluenceconsumption.
Studies of impacts of taxes on items such as soda typically find small effects, if any.Lookingatdataonadolescents,Powelletal.(2009)foundnostatisticallysignificantassociationsbetweenstate-leveltaxesonsoda(SSBs)andadolescentBMI.AweakeconomicandstatisticallysignificanteffectwasfoundbetweenratesoftaxonsodasoldinvendingmachinesandBMIamongteenagersatriskofbecomingoverweight.
PowellandChaloupka(2009)reviewedliteraturepublishedbetween1990and2008toexaminewhethertaxesorsubsidieswouldleadtosufficientchangesinpatternsoffoodconsumptionandoveralldiettoreducepeople’sweights.Whenstatisticallysignificantlinkswerefoundbetweenfoodandrestaurantprices(taxes)andweightoutcomes,effectsweregenerallysmall.Largereffectswereseenamongpopulationsoflowersocio-economicstatus,aswellasforthoseatriskofoverweightorobesity.Theyconcludedthatthe(limited)evidenceavailable(dealingentirelywithsmalltaxesorsubsidies)indicatedthatsmallincentiveswouldnotbelikelytoyieldsignificantchangesinBMIortheprevalenceofobesity,thoughstrongerinterventionsmayhavesomemeasurableimpactonweightoutcomesintheUSA,especiallyforchildren,adolescents,populationsoflowsocio-economicstatus,andthosemostatriskforoverweight(PowellandChaloupka2009).
Likewise,Sturmetal.(2010),lookingatchildrenfromkindergartentograde5,foundexistingtaxesonsoda(typicallynotmuchhigherthan4%)didnotsubstantiallyaffectoveralllevelsofsodaconsumptionorobesityrates.Somesub-groupsofat-riskchildren–thosealreadyoverweight,fromlow-incomefamilies,orAfricanAmericans–werefoundtobemoresensitivethanotherstosodataxes,particularlywhensuchSSBswereavailableinschools.
Fletcheretal.(2010)foundnoevidencethattaxesonsoftdrinksorrestrictionsonvendingmachinesaffectedtheBMIofchildreningrades5and8.Analysesoftherelationshipbetweensodataxestoweightoutcomesshowedminimalimpacts(Powelletal.2013).
Schroeteretal.(2006)havegonesofarastosuggestataxonfoodawayfromhome–acategoryofconsumptionimplicatedintheriseofobesity–mightactuallyleadtoincreasedobesity.Theirmodelshowedthatwhiletaxingmealsawayfromhomemayreducethefrequencywithwhichpeopleconsumethem,thesubstituteofeatingathomemayactuallyleadtomorecaloriesbeingconsumed,sincesomuchofthefoodeatenathomeisenergy-rich.
Thesestudies,however,lookedattheimpactsofrelativelylowtaxes,8typically5%orless,onasinglefoodthatmightaccountforlessthan10%ofcalorieintake.
3.1.7 Summary of the US literatureAconsensusemergesfromthisliterature,evenifcontraryfindingsandqualificationscanbefoundinthemanystudiesreviewed,asfollows:
• Moststudiesfindthathealthierfoodscostmorethanlesshealthyones.Moreoverthiseffecthasincreasedoverthelast30–40years,asenergy-dense,processedfoodshavebecomecheaperrelativetolessenergy-densefruitandvegetables.
• Consequentlyhealthydietstendtocostmorethanlesshealthydiets.Thatisnotinevitable:choosinglowercosthealthyitemsandsubstitutingthemforthemorecostlylesshealthyonesmightbothimprovedietandsavemoney.Butformostconsumers,thiswouldrequireboththeabilitytoseethedistinctions,andthedisciplinetofollowaparticulardiet.
• Althoughitseemssomeenergy-denseprocessedfoodshavebecomenotablycheapercomparedtofruitandvegetables,thenatureofthelatterhavechanged–withhigher-valueprepareditemscommoninfoodoutlets,andavailablealltheyearround.Takingthisaddedvalueintoaccountthechangeinrelativepricesmaybelessthanisatfirstapparent.
• Consumptionofmostfoodsrespondstopricechanges,althoughformanyfoodstheresponseisrelativelyinelastic.Thoseonlowincomesaremostlikelytorespondtochangingprices.
Thisfindinghasbeendilutedbystudiesoftheimpactsoffoodtaxesthatoftenseemtotriggertinychangesinconsumption.Althoughfoodindustrylobbyistsusesuchstudiestoargueagainsttaxes,thetaxesstudiedormodelledarealmostalwaysverysmall,5%orlessbeingtypical.Ithasneverbeenexpectedthata5%taxonSSBs,forexamplewouldcausealargereductionintheirconsumption.
• StudiesoftheimpactsofchangesinpricesonbodyweightproduceasurprisinglystrongconsensusthathigherpricesofunhealthyoptionsreduceBMI,asdocheaperhealthieroptions.‘Surprising’sincebodyweightistheoutcomeofmanyfactors,yetpricechangescanbeseentomakeadifference.Thestrongesteffectsareseenamongthoseonlowincomes,whoaremostsensitivetothecostoffood.
8 Around3%to5%(someacademicssuggestSSBtaxshouldbeat20%–seehttps://www.fmhs.auckland.ac.nz/en/soph/global-health/projects/informas/government-healthy-food-environment-policy-index.html).
3.2 United Kingdom
3.2.1 Background: obesity in the UKOverweightandobesityratesintheUKarealmostashighasUSratesandsignificantlyhigherthaninmostEuropeancountries.In2008,around68%ofadultmalesintheUKwereestimatedtobeoverweightorobese,while61%ofadultfemalesfellintothiscategory(datafromStevensetal.2012).9Some9%ofUKchildrenarealreadyclassifiedasobesewhentheystartschool,risingto19%inyear6(LGA2014).Children’sobesityvariesbyinequality,witharound25%ofthemostdeprivedchildren(byquintileofdeprivation)agedfrom10to11inLondonin2007/08obese,comparedtoaround13%oftheleastdeprivedquintile(seeFigure11inTheMarmotReview2010).
In2006/07,overweightandobesitycosttheNationalHealthService(NHS)£5.1billion10–morethanthecostofsmoking(£3.3billion),alcohol(another£3.3billion)orphysicalinactivityalone(£0.9billion)(Scarboroughetal.2011).ItisestimatedthatoneinsevenhospitalbedsintheUKisoccupiedbyapatientwithdiabetes,whilethenumberofadmissionstoNHShospitalswithaprimarydiagnosisofobesityrosefrom1,019in2001/02,to11,736in2011/12(LGA2014).
TypicalUKdietsarenotbalancedinaccordancewithdietaryrecommendations,withexcessiveconsumptionofgrainsandotherstarchyfoods,protein-richfoods,oils,fats,andsugar–coupledwithparticularlylowintakeoffruitandvegetables.
StudieshaveshowndecliningenergyintakesintheUK.PrenticeandJebb(1995)reporteddeclinesinsomemeasuresofenergyintakeandmorerecentlyGriffithetal.(2013)confirmedthetrendforlowerconsumptionofdietaryenergyintheUKfrom1980to2009,withsignificantreductionsincaloriesboughtforhomeconsumptiononlypartlyoffsetbytherisingshareofeatingoutinaggregateconsumption.PrenticeandJebb(1995)therebyinferredthatrisingobesitywastheresultoftoolittleactivity:‘moderninactivelifestylesareatleastasimportantasdietintheaetiologyofobesityandpossiblyrepresentthedominantfactor’.Debateonthiscontinues,somearguingthatrepresentingthemaindriversas‘sloth’or‘gluttony’is‘overlysimple’(Robertoetal.2015).
3.2.2 UK trends in relative prices The relatively few studies in the UK show healthy diets to be more costly than less healthy diets
Capaccietal.(2012)usehouseholddatafortheUKfrom1997to2009toestimatepricesof‘healthy’and‘unhealthy’bundlesoffoods.Theformerwererestrictedforsimplicitytofruitandvegetables,excluding
potatoes;whilethelatterwerethe‘bigsix’foodgroups–confectionery,softdrinks,crisps/savourysnacks,fastfood,pre-sugaredbreakfastcerealsandpre-preparedconveniencefoods;thatis,thosecategorisedbytheFoodStandardsAgency(FSA)ashighinfats,sugarandsalt(HFSS)forthepurposesofadvertisingregulationssetbytheOfficeofCommunications(Ofcom),apublicregulator.
Theyestimatethatpricesoffruitandvegetablesincreasedbyabout7%relativetoallfoodsoverthe13-yearperiod,whilethepricefor‘junk’foodrelativetoallfoodsfellbyabout15%(seeFigure3.6).
Sincetheyanalysedunitvalues,thatisspendingdividedbyquantity,ratherthanobservedprices,theylaterproducedacorrectiontoinferprices.Thedifferencearisessincewhenaspricesofagroupoffoodsrises,consumerstendtoswitchtowardscheaperitemswithinthegroupincludinglowerqualityitems,sotheiraverageunitvaluedoesnotriseinlinewithprices.
Jonesetal.(2014)classified94foodsandbeveragesintheUKas‘morehealthy’or‘lesshealthy’accordingtoanutrient-profilingmodeldevelopedbytheFSA.Meanpricesin2012were£2.50forlesshealthyand£7.49formorehealthyitemsbyunit,whileby1,000kcallesshealthyitemscost£0.29,whilemorehealthyitemscost£1.27.Moreover,whileallpricesrosefrom2002to2012,thepricesofmorehealthyitemsrosesignificantlyfasterthanlesshealthyonesinabsoluteterms:£0.17comparedto£0.07/1,000kcalperyearonaverageformoreandlesshealthyitems,respectively.
9 Interestingly,whileinmentheprevalenceofobesitygrewacrossdifferentjobcategoriesfrom1997to2007inasimilarfashion,inwomen,prevalenceofobesityincreasedacrossalljobcategoriesexcept‘professional’,whereitbarelyshiftedatalloverthetimeperiod–seeFigure11.10inAnnexII.
10 Incomparison,England’sspendingonpreventivehealthinterventionsforobesity,dietandlifestylein2006/07wasonly£116million(seeTable4.3inTheMarmotReview2010).
Figure 3.6: Fruit and vegetables and ‘junk’ food, unit values and corrected prices relative to total food
Source: Figure 1 in Capacci et al. 2012
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Comparingthedifferencesin‘healthy’and‘unhealthy’dietcostsforagroupofover15,000UKwomenaged35to69,11Cadeetal.(1999)classifieddietsintoeightgradesofhealthiness,basedonWHOrecommendations.12Womeninthehealthiestgroupspentonaverage64%moreontheirfoodthanwomenintheleasthealthygroup(£2.33perdaycomparedto£3.81perday).Theyalsospentalmosthalfoftheirfoodbudgetsonfruitandvegetablescomparedtolessthanathirdintheleasthealthygroup,andfarlessonmeat—indeed,womeninthehealthiestdietgroupwerealmostfourtimesaslikelytobevegetarian.Figure3.7showsabreakdownoftheirdifferentdietcostsbyfoodgroup.
Alaterstudyusedthesamewomen’scohortstudydatafor1995–98toinvestigateasimilarquestion,classifyingdietsinaslightlydifferentway13accordingtohowwelltheyadheredtotheUKDepartmentofHealth’s‘EatwellPlate’,aguidetothecompositionofahealthydiet(Morrisetal.2014).Theysimilarlyconcludedahealthydietwasmoreexpensivethanalesshealthyone,withthehealthiestcostingtwicethepriceoftheleasthealthy,£6.63perdayand£3.29perday,respectively.
WriedenandBarton(2011)lookedspecificallyatenergy density ofdietsinScotland,andcomparedcostsofenergy-denseandlessenergy-densediets.Separatinghouseholdsintoquintilesofenergydensityshowsthe
quintilewiththeleastenergy-densedietconsumesapproximately123kcalper100goffoodandmilk,whilethoseinthequintilewiththemostenergy-densedietsconsume231kcalper100goffoodandmilk.TheWCRFrecommendsnotexceedingadietaryenergydensityonaverageof125kcalper100goffood.
Moreover,thecostpaidper2,000kcalforhouseholdsinthelowestquintileofenergydensityisalmost£5,whiletheequivalentcostforhouseholdsinthehighestquintileis£3.76(seeFigure3.8).
Dietsweremoreenergy-denseonaverageforsingle-parenthouseholds(183kcal/100g)andotherhouseholdswithchildren(177kcal/100g)thanforhouseholdswithoutchildren(single-personhouseholds,forinstance,ateanaverageof169kcal/100g).Meanenergydensityforfoodandmilkconsumedinthe309householdsmeetinghealthtargetsforfatconsumption(<=35%offoodenergy)andfruitandvegetableconsumption(>400g/day)was136kcalper100g.Forthe3,859householdsnotmeetingthesetargets,theequivalentfigurewas175kcal/100g.
IfhealthierdietscostmoreintheUK,thefearisthatpeopleonlowincomesmaynotbeabletoaffordthem.Banksetal.(2012)reportthisisnotnecessarilythecase,andindeedthetypeoffoodretailerplaysmoreofaroleinthecostoffoodthandodifferencesinfoodchoicebetweenhealthyandlesshealthyoptions(seeBox3A).
11 DatafromtheUKWomen’sCohortStudycollected1995–1998.
12 WHOhealthydietindicatorcomponentsincluded:percentageoftotalenergyfromsaturatedfattyacids,frompolyunsaturatedfattyacids,fromprotein,fromcomplexcarbohydrates,andfromfreesugars(excludingfructoseandlactose);gramsofdietaryfibre,offruitandvegetables,ofpulses,nuts,andseeds.
13 Theylookedatsevendietarypatterns,withadiethealthinessscorefrom1to5.Worstdietsweredescribedas‘Monotonouslowqualityomnivore’(scoreof1),followedby‘Traditionalmeatchipsandpuddingeater’(2);‘Conservativeomnivore’and‘Lowdiversityvegetarian’(3);‘Higherdiversitytraditionalomnivore’and‘Highdiversityvegetarian’(4);and‘Healthconscious’(5).
Figure 3.7: Contribution of different food groups to daily diet costs of healthiest and least healthy group of eaters, adult women, UK, 1995–98
0.19 0.33
0.64
1.870.42
0.05
£0.00
£0.50
£1.00
£1.50
£2.00
£2.50
£3.00
£3.50
£4.00
Least healthy dietgroup
Most healthy dietgroup
Diet
cos
t per
day
Alcoholic beverages
Non-alcoholic beverages
Sauces/soups, savourysnacks, sweetsDairy, eggs, margarine,spreadsFish
Meat
Grains/nuts/seeds
Vegetables, fruit
Bread, cereals, potatoes,pasta, rice
9 8
29
49
17
1
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Least healthy dietgroup
Most healthy dietgroup
Prop
ortio
n of
die
t cos
t
Source: Data from Table 3 in Cade et al. 1999
3.2.3 Price changes and consumptionArecentrathercomprehensiveanalysis,correctingshortcomingsinearlierwork,hasassessedown-andcross-priceelasticitiesforalargesetoffoodgroups,acrossincomeandgeographicalsub-setsoftheUKpopulationfrom2001/02to2009(Tiffinetal.2011).Own-priceelasticitiesforfoodgroupsrangefromtheelastic-1.38forfruitandnutstotherelativelyinelastic-0.58formeat.(seeTable3.3).
Theauthorsthenusedtheseelasticitiestoseehowchangesinfoodpricesandfoodexpenditurewouldaffecttheintakeofnutrients–wherecross-priceeffectsbecomesignificant.Forexample,higherpricesoffatandstarch,dairyandeggproductswouldleadhouseholdstoconsumelessfatandenergy,asmightbeexpected;buttheywouldalsoleadtolowerconsumptionofvitaminsandmicronutrients.A10%increaseinthepriceof
dairyandeggproductsreducestheintakeofbeneficialnutrientssuchascalcium(-3.8%),iron(-3.5%),vitaminD(-4.6%)andzinc(-8.4%).Theeffectsofsubsidiescanbemodelled.Subsidisingvegetablesby5%increasesvegetableconsumptionoflow-incomehouseholdsby3.23%,butalsoraisesconsumptionofmeatby0.45%,decreasesalcoholby0.62%,decreasesfishby0.23%,andhasanegligibleeffectondairy,eggs,fatsandstarches.Itwouldincreasetheintakeofcarotenes(+2%),VitaminC(+0.8%)andfibre(+0.5%).
Somestudieshavelookedattheinfluenceonpurchasingofsalespromotionsthataffectprices.Hawkes(2009a)synthesisedtheliterature(notonlyfromtheUK)ontheinfluenceofsalespromotionsonfoodconsumption.Althoughpromotionsleadtosignificantsalesincreasesovertheshortterm,itwasnotclearifchangesinfoodconsumptionwouldpersistafterthepromotion,owingtolackofinformationonlonger-termeffects.
Figure 3.8 Diet costs (per calorie) and energy density, Scotland, 2011
£4.97£4.84
£4.40
£4.28
£3.76123
151
167
187
231
100
120
140
160
180
200
220
240
£3.50
£3.70
£3.90
£4.10
£4.30
£4.50
£4.70
£4.90
1 (least dense) 2 3 4 5 (most dense)
Quintile of energy density (food and milk)
Kcal
per
100
g
£ pe
r 200
0kca
l
Household and eating out combined cost Food and milk energy density - R axis
WCRF energy density recommendation - R axis
Source: Compiled fom data in Table 10 in Wrieden and Barton 2011
Notes: WCRF = World Cancer Research Fund. Kcal = kilocalories
Table 3.3: Estimates of food price elasticity in the UK, long-runChange in consumption in response to price change
Dairy & Egg Meat Fish Fruit & Nuts Veg. Fats & Starches Alcohol Expend.
Dairy&Eggs -1.00 -0.01 0.04 0.20 0.05 -0.13 0.01 0.85
Meat -0.09 -0.58 0.04 -0.03 0.08 -0.48 -0.09 1.14
Fish 0.56 0.29 -0.70 -0.43 -0.01 -0.26 -0.09 0.64
Fruits&Nuts 0.38 0.01 -0.06 -1.38 -0.01 0.38 -0.07 0.76
Veg. 0.12 0.12 0.00 -0.01 -0.65 -0.32 0.03 0.72
Fats&Starches -0.09 -0.09 -0.01 0.07 -0.10 -0.83 0.04 1.02
Alcohol -0.27 -0.28 -0.05 -0.35 -0.10 -0.28 -1.12 2.46
Source: Table 4 Tiffin et al. 2011
32 ODI Report
The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 33
Box 3A: Cheap eats and healthy treats: affordable for families of obese children in the UK?
Affordabilityisoftencitedasafactorinpeople’sunhealthydiets.Arecentrandomisedtrialofobesechildrenagedfiveto16lookedatthisquestion,comparingtheiractualdietstoatheoretical,healthydietbasedontheEatwellPlate.Thehealthydietswereonlyslightlyadjustedversionsofthechildren’sexistingdiets–amoreacceptableoptionthanpricinganalternativedietfarremovedfromexistingones.Figure3A1showssomeexamplesofadjustmentsbetweenexistingandhealthydiets,andtheimpacttheywouldhaveonenergyintake.
Figure 3A1: Kcal changes associated with adjusting meals to healthier options
-300 -200 -100 0 Original meal Healthier option
2sliceswhitetoast,paté,crisps,cola,largeportionHoneynutCheerios®,semi-skimmedmilk
2sliceswhitetoast,low-fatbutter,apple,semi-skimmedmilk,1portionCheerios®,banana
Portionfriedchicken Portionroastchicken
Crisps,3sliceswhitebread,butter 4sliceswhitebread,roastchicken,LFbutter,salad
3slicesofpizza 2slicesvegetablepizza,mixedsalad,orangejuice
1packready-madelasagne ½packoflasagne,carrots,apple
Cola Zerocola
½pintblackcurrantsquash ½pintno-sugarblackcurrantsquash
1sliceofcheesecake,cream 1 fruit ice pop
1packofHaribo®Jellies 1portionricepuddingwithSSmilk
Source: Data from Table 1 in Banks et al. 2012
Bothdietswerepricedatthreeshops:aneighbourhoodmid-rangesupermarket,abudgetsupermarket,andthelocalhighstreet.Thechildren’sactualdietboughtatabudgetsupermarketwasthecheapest(£2.48/day).Thehealthieroptionatthesameshopcostanadditional33pence/day(£2.81).Thesameexerciseinamid-rangesupermarketincurredanadditionalcostof4penceperday(£3.40versus£3.44).
Shiftingfromtheunhealthyoptionboughtatamid-rangesupermarkettothehealthier,budget-outletoptioncouldsave59penceperday.Thehealthieroptionwascheaperthantheexistingdietifpurchasedonthehighstreet(£3.58versus£3.75),althoughforbothmenusthehighstreetwasthemostexpensiveoption–seeFigure3A2.Evenifswitchingfromtheexistingtoabudgetsupermarkethealthydiet,theextracostwouldbeonlyabout£10permonth.
Figure 3A2: Cost of different diets from three types of shop
2.48
3.4
3.75
2.81
3.443.58
£2.00
£3.00
£4.00
Budgetsupermarket
Supermarket Independentshops
Existing diet
Healthy diet
Source: Data from Table 3 in Banks et al. 2012
Theyconcludedthatformanyofthefamiliesofobesechildren,theextracostofeatinghealthilywouldnotnecessarilybeprohibitive,thoughcostmaybeabarrierforthemostdisadvantaged.Source: Banks et al. 2012
Studyingthespecificcaseoftheimpactofpromotionsonsugaryfoodpurchases–take-homeconfectionary,frozenconfectionaryandicecream,andnon-dietsoftdrinks–inScotlandbetween2006and2011,Revoredo-GihaandAkaichi(2014)foundthatconsumersdidindeedrespondtopromotionsonsugaryfoods.Inparticular,familieswithchildrensignificantlyincreasedpurchasesofsugaryproductsoverthesixyearsreviewed,owinginlargeparttopricepromotions.Moreover,theuseofsuchpromotionsbythefourlargestScottishsupermarketsincreasedovertime,suggestingthatretailersusedpromotionstokeeppeoplespendingovertherecession.
3.2.4 Effect of price changes – including taxes – on consumption and health in the UK
Severalstudieshavemodelledthelikelyimpactoftaxesandsubsidiesoneatinghabits,weightorhealth.
Briggsetal.(2013)modela20%taxonSSBsontheprevalenceofoverweightandobesityofpeopleaged16andoverintheUK.Own-priceelasticityforSSBis-0.92forconcentratedand-0.81fornon-concentrateddrinks,sothata20%taxonSSBdecreasesconsumptionoftheformerby15%andthelatterby16%.Tocompensate,consumptionofotherdrinksrises.Consumersonhigherincomestendtoswitchtowater,whilethoseonlowerincomesswitchtodietsoftdrinks,milk,andfruitjuice.
Annualrevenuefromsuchataxwasestimatedat£276million.Totalexpenditureondrinkswouldrisebyfor2.1%forthehighestincometercile,by1.7%forthemiddletercile,andby0.8%forthelowesttercile.ThetaxwouldreducethenumberofobeseadultsintheUKby1.3%(or180,000people),andthenumberofoverweightby0.9%(285,000people).Effectsonobesitywerestrongeratyoungerages,leadingtheauthorstoconclude:‘Taxationofsugarsweeteneddrinksisapromisingpopulationmeasuretotargetpopulationobesity,particularlyamongyoungeradults’(Briggsetal.2013).
Myttonetal.(2007)examinetheeffectsonnutrition,healthandexpenditureofextendingVATtoawiderrangeoffoodsintheUK.ConsumptionpatternsandelasticitydataweretakenfromtheNationalFoodSurveyofGreatBritain,14whilethehealtheffectsofchangingsaltandfatintakewerefrompreviousmeta‐analyses.Threescenarioswereconsidered:ataxonthemainsourcesofsaturatedfatindiets;ataxonfoodsdefinedasunhealthybyanutrient-profilingmodeldevelopedfortheFSA;andataxonfoodstoobtainthebesthealthoutcome.
Inthefirstscenario,theyfindthattaxingonlythekeysourcesofdietarysaturatedfatisnotlikelytoreduceprevalenceofcardiovasculardisease(CVD),mainlybecauseafallinsaturatedfatisoffsetbyariseinsalt
consumption.Inthesecondscenario,theyfindthattaxingunhealthyfoodsmightpreventsome2,300deathsperyear,chieflybyreducingsaltintake.Finally,inthethirdscenario,theyfindthatataxonawiderrangeoffoodscouldpreventupto3,200CVD-relateddeathsintheUKperyear,areductionof1.7%.Theauthorsconcludethatwhileataxoncertainfoodscanleadtounpredictablehealtheffectsifcross-priceelasticitiesofdemandarenottakenintoconsideration,acarefullytargeted‘fattax’couldhaveamodestbutmeaningfulinfluenceonpeople’sdietsandontheincidenceofCVD.
Inarelatedstudy,Nnoahametal.(2009)exploresimilartaxscenarios,aswellastax-subsidyscenarios,toassesstheimpactonmortalityfromnotonlyCVD,butalsocancer.TheyfindthatataxontheprincipalsourcesofdietarysaturatedfatisunlikelytoreduceCVD15orcancermortality.Indeed,ratherthanpreventingdeaths,itleadstoextradeathssincealthoughfatconsumptionfalls,sotoodoestheconsumptionoffruitandvegetablesowingtocross-priceelasticities.Ataxon‘lesshealthy’foods(definedaccordingtotheFSAnutrient-profilingmodel)couldevenincreaseCVDandcancerdeathsby35to1,300ayear,forsimilarreasons.
Incontrast,ataxon‘lesshealthy’foodscombinedwithasubsidyonfruitandvegetablesof17.5%couldavertupto2,900CVDandcancerdeathseveryyear,whiletaxing‘lesshealthy’foodsandusingalltaxrevenuetosubsidisefruitandvegetablescouldavertupto6,400CVDandcancerdeathsayear.Eachscenariowouldplaceahighereconomicburdenonlower-incomefamilies.Inthelasttwoscenarioshowever,manyofthelivessavedthroughtax-subsidyschemeswouldbethoseofpoorerpeople.
2.5 Summary of the UK literature
• Healthydietscostmorethanlesshealthydiets. • Overthelast10–20years,thecostoffruitandvegetableshasrisencomparedtootherfoods,andespeciallyprocessedfood.
• Cross-priceeffectsmatterinassessingthenutritionaleffectsofpricechanges.Taxesonfatorsaltcontentmayaffectconsumptionofother,complementaryfoods,leadingtolowerintakeofbeneficialnutrients.Usingtaxrevenuestosubsidisesuchcomplementaryfoodswouldcounterthiseffect.
14 TheelasticitiesusedhereandinNnoahametal.(2009)describedbelowarethesameasthosecriticisedbyTiffinetal.(2011)forbeingcalculatedonthebasisofoutdatedeconomicandstatisticalapproaches.
15 Thoughitreducescoronaryheartdisease(CHD),itincreasesstrokesbyagreaterextent.
34 ODI Report
The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 35
3.4 Brazil
3.4.1 Consumption of (ultra) processed foodConsumptionofultra-processedfoodanddrink–thatis,ready-to-eatordrinkandfoodsthathavebeenindustriallypreparedfromingredients,typically‘energy-dense,fatty,sugaryorsalty,andformulatedtobehyper-palatable’(Monteiroetal.2012)–hasbeenrising,fromjustover80kgpercapitaperyearin1999toaround110kgpercapitaperyearby2013(Moubarac2014).Consumptionofsugarydrinks,asmodelledfromEuromonitordata,wasamongthehighestformiddle-andlow-incomehouseholds(Basuetal.2013).Someultra-processedfoods,suchasbreadandsausages,havelongformedpartofBraziliandiets,whileotherssuchascrisps,biscuits,energybars,andsugarydrinksaremorerecentadditions,encouragedbywidespreadmarketing(seeBox3B).
From1990to1996householdsinSãoPauloincreasedtheirspendingon‘industrialised’(highlyprocessed)food,whilespendinglessonsemi-preparedandnon-processedfoods(BarrettoandCyrillo2001).Morerecently,between1996and2009,surveysshowconsumersgettingsmallersharesofenergyfrommoretraditional,minimallyprocessedfoods,asthecontributionofultra-processedproductshasgrown(seeFigure3.9).
Energy-densefoodstendtobecheaperpercaloriethanotherfoods(seeFigure3.10).Mostoftheraworminimallyprocessedfoods–suchasfruitsandvegetables–havehighercostspercaloriethandothemoderatelyprocessedfoods–suchassugarandoils.Intermsofcostperkilocalorie,manyofthehighlyprocessedfoodswerealsorelativelycheap,exceptforreadymeals(RicardoandClaro2012).
3.4.2 Effect of food prices and incomes on consumption
Lookingattheinfluenceofthepriceoffruitandvegetablesontheircontributiontopeople’sdietsinBrazil,ClaroandMonteiro(2010)showedthata1%
fallintheirpricewouldincreasetheircontributiontocalorieintakeby0.79%.ForSãoPauloalowerelasticityofdemandwasfound,a1%pricefallleadingtoonlya0.2%increaseinconsumptionbycalorie(Claroetal.2007).Theyalsorecordedasmallcross-priceelasticity:a1%increaseinthepriceofotherfoodswouldincreasefruitandvegetablecontributiontocalorieintakeby0.07%.
Incomeelasticitieswerealsoreported.ForBrazilasawhole,theincomeelasticityofdemandforfruitandvegetableswasestimatedat0.27(ClaroandMonteiro2010),andforSãoPauloat0.04(Claroetal.2007):thatis,highlyinelasticresponsestoincome,althoughinbothcasesresponsesweregreateramongthoseonlowincomes,aswouldbeexpected.
Pricesareonlyoneinfluenceonfoodchoice:astudyofthedietsofwomenaged20to60yearsinurbanSãoLeopoldoinsouthernBrazil,(Lenzetal.2009)foundthathealthydietsweremorefrequentamongwomenwithhigherincomesandeducationallevel,whilewomenwithlowerincomesandlesseducationweremorelikelytoconsumedietswithhigherhealthrisks.
Figure 3.9: Proportion of energy from different food groups, urban household purchases, Brazil, 1996–2009
Source: Monteiro 2013
Box 3B: Marketing of processed food in Brazil
MonteiroandCannon(2012)seepowerfultransnationalfoodandsnackcompanies–dubbed‘BigFood’and‘BigSnack’–playingamajorroleinpeople’sincreasingconsumptionofultra-processed,fastorconveniencefoods.SuchfoodsareincreasinglydifficulttoavoidincontemporaryBrazil:
…wewentforlunchtoaworkers’restaurantneartheUniversityofSãoPaulo,whereatraditionalfreshlycookedmealofrice,beans,andachoiceofmeat,togetherwithmixedsalad,costtheequivalentof$US6.Wenoticedthatthebottledwaterofferedwas‘made’byaonceBraziliancompanynowownedbyCoca-Cola,andthattheartisanalwater-basedicelolliescontainingfruitjuice,whicharestillsoldbypedlarsonBrazilianbeachesandsuppliedbytraderstosimplerestaurants,hadbeenreplacedbyfatty,sugarybrandsofNestléicecream.Thesesameicecreams,togetherwithotherNestlé‘popularlypositionedproducts’,whichare‘targetedatandboughtbylowincomeconsumers’,arenowbeingsolddoor-to-doorintheoutskirtsofseveralBraziliancities,ontrainsandsubwaystations,inretailchainsthatsellelectronicandhouseappliances,andalsoon‘floatingsupermarkets’thattakeNestléproductstoremoteAmazonianvillages.(MonteiroandCannon2012)
4.3 Food taxesTaxesonlesshealthyfoodsmaybeparticularlyeffectiveinBrazil.InvestigatingtheeffectofataxonSSBs,Claroetal.(2012)usedhouseholdfood-consumptiondatacollectedin2002–2003forasampleofover48,000householdsinBrazil.Controllingfordemographicvariables,income,andpricesofotherfoodsanddrinks,theyfoundthatanincreaseinthepriceofsugarydrinksledtoreducedconsumption:a1%priceincreaseledtoa0.85%reductionincaloriesfromsugarydrinks.Thiseffectwasstrongerforpoorpeople(1.03%reduction),thanfornon-poor(0.63%reduction).Suchhighelasticitiessuggestthattaxesmighthaveastrongeffect,particularlyamongpoorerpeople:ataxof30%ontheaveragepriceofsugarydrinkswouldreduceaverageconsumptionbyabout25%(Claroetal.2012).
Figure 3.10: Cost per kilocalorie for different food groups in Brazil
$5.14
$3.45
$0.65
$1.90
$0.27 $0.34 $0.56 $0.39
$1.59
$2.38
$5.18
$2.06 $1.90
$0.00
$1.00
$2.00
$3.00
$4.00
$5.00
$6.00
Frui
ts, v
eget
able
s an
d gr
eens
Mea
ts, e
ggs,
and
milk
Stap
les
(cer
eals
, gra
ins,
tube
rs a
ndbe
ans)
Aver
age
for g
roup
1
Suga
r
Oils
and
fats
Flou
rs a
nd p
asta
Aver
age
for g
roup
2
Brea
ds, b
iscu
its, a
nd c
akes
Proc
esse
d m
eats
Read
y m
eals
Othe
r pro
cess
ed fo
ods
Aver
age
for g
roup
3
Group 1 (raw or minimallyprocessed)
Group 2 (moderatelyprocessed)
Group 3 (highly processed)
Braz
ilian
Rea
l per
1,0
00 k
cal
Source: Table 3 in Ricardo and Claro 2012
36 ODI Report
The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 37
3.5 China
3.5.1 Food prices in ChinaCookingoilhasbecomecheapercomparedtootherfoodsinChina(seeFigure3.11)(LuandGoldman2010).
3.5.2 Effect of food prices on weight in ChinaToassesstheeffectsofrelativefoodpricesonbodyweightandbodyfatovertime,LuandGoldman(2010)usedacohortstudyof15,000adultsfromover200communitiesinChinafromtheChinaHealthandNutritionSurvey(CHNS)from1991to2006.Theyfoundthatdecreasesinthepriceofenergy-densefoodsledtogreaterbodyfat;aneffecttheycouldnotalwaysfindforbodyweight,leadingthemtoconclude:
…changesinfoodconsumptionpatternsinducedbyvaryingfoodpricescanincreasepercentagebodyfattoriskylevelsevenwithoutsubstantialweightgain.Inaddition,foodpricesandsubsidiescouldbeusedtoencouragehealthierfoodconsumptionpatternsandtocurbobesity.(LuandGoldman2010)
AlsousingdatafromtheCHNS,He’s2013studyofchildobesityfromthemid-1980stothemid-2000sfoundanobesogenicenvironmenttobeamuchmoreimportantfactorinshapingobesity-relatedriskbehaviourthanwasthemoreindividualdeterminant‘willpowerbasedonknowledge’.Interestingly,givenhowoftenruralparentsmigrateforworkandleavechildreninthecareofelderlyfamilymembers,shealsofound:
Childreninthecareofgrandparentsarehealthier,probablyduetothegenerallylowdegreeofaccesstoobesogenicfoodsandacloserintergenerationalrelationshipthatfacilitateseffectivecommunicationandpromoteshealthylifestyleformation.(He2013)
James(2008)seesthelong-termfallinpricesoffatsandoilscomparedtomoreexpensiveproductslikefish,meat,dairy,andfruitandvegetables,ascontributortogrowingobesityinChina.
3.6 Republic of Korea
3.6.1 Consumption trendsSofar,theRepublicofKoreahastakenwhatsomedescribeasauniquetrajectorythroughthe‘nutritiontransition’(seePopkinetal.2012),asaresultofstrongeffortstomaintainatraditionalKoreandietlowinfatandhighinvegetablesinthemidstofrapideconomicgrowthandWesternisation(Leeetal.2002).Thoughlargeshiftscanbeseenoverthepastdecade,drivenbyanincreasingopennesstoimportingfood,veryhighvegetableandmodestfatconsumptionseemto
havepersisted(Leeetal.2012).Estimatesofvegetableconsumptionperperson,particularlykimchi,haveremainedinmostyearsbetween260and290gramsadaysince1969(seeFigure3.12).
Somelesspositivetrendshavebeenspotted,however,withaveragedailyalcoholintakerisingfrom39kcalto82kcalperpersonbetween1998and2009,aswellasenergyintakefromSSBrisingamongteenagers(Leeetal.2012).Hanetal.(2013)documentedrisingprevalenceofSSBconsumptionamongadolescentsandallolderagegroupsbetween2001and2009:
SSBconsumptionprevalenceincreasedto38%,69%,70%,and50%by2009upfrom31%,66%,63%,and32%in2001amongadolescents,youngadults,adults,andtheelderly,respectively.
TheprevalenceofSSBconsumptionwashigheramongindividualsofrelativelyhighsocio-economicstatus,particularlyinthecaseoffruitdrinksandmiscellaneousSSBs–sports/energydrinks,coffee/teaproductsandflavouredmilk–ratherthansoda.
Astudyofchildandadolescentconsumptionfor2008–2011foundthatonaverage,childrenagedsevento12drankaround65mlofSSBsaday,whilechildrenaged13–18drank120mladay.Some12%ofchildrenandadolescents,however,weredrinkingmorethan300mlofSSBaday.Leeetal.(2013)foundhigherconsumptionwasassociatedwithhighoverallenergyintake,butlowconsumptionofmilk,fruitandvegetables(notmeetingthe400gadayrecommendationforthelatter).Furthermore,theyfoundthatbeingoverweightandobesewassignificantlyassociatedwithgreateroddsofhighSSBconsumptionamongboysaged7–12years.
Figure 3.11: Cooking oil prices, China, 1991–2006
Source: Figure 1 in Lu and Goldman 2010
3.7 Mexico
3.7.1 Consumption of ultra-processed food and drink
Mexico’sconsumptionofprocessed,oftenunhealthy,foodhasskyrocketed(seeFigure3.13).MexicohasledLatinAmericainpercapitaconsumptionofultra-processedfoodanddrinks.
MexicanconsumptionofsoftdrinksperpersonismuchhigherthanmightbepredictedbyitspercapitaGDP(Basuetal.2013)(seeFigure3.14):in2008,dailyconsumptionwasalmostonethirdmorethanintheUSA.
Sternetal.(2014),using24-hourdietrecallstudiesfrom1999and2012withnationallyrepresentativesamples,foundthattotaldailyenergyfrombeveragesincreasedbyabout45kcalforchildrenagedfiveto11,by57kcalforgirlsandyoungwomenaged12to19,andby96kcalforadultwomenaged20to49.
3.7.2 Food prices in Mexico
TherealpriceofmanybeveragesdecreasedovertimeinMexico,correspondingtolargeincreasesinMexicanconsumptionofenergy-containingbeverages–wholemilk,carbonatedandnon-carbonatedSSBs,fruitjuicewithvarioussugarandwatercombinationsadded,andalcohol–between1999and2006,sothatby2006,adultsandadolescentsobtained22%and20%respectivelyoftheirenergyintakefromthesebeverages(Barqueraetal.2008).
Figure 3.12: Vegetable consumption in Republic of Korea, 1969–2009, grams per person per day
58 79 91 109 96 80124 102 114 113 117
213 158
191 153 177
144
162181 177
214169
271
237
281262 273
224
286 283 291
327
286
0
50
100
150
200
250
300
350
1969 1973 1977 1981 1985 1989 1995 1998 2001 2005 2009
g/ca
pita
/day
Other vegetables Kimchi Total vegetables
Source: Figure 2 in Lee et al. 2012 Note: Values are presented as three-year or four-year moving averages. Kimchi intake is presented as a mean
from age>=1 between 1969 and 1995, and from age>=2 from 1998 to 2002.
Figure 3.13: Annual sales of selected ultra-processed foods and drinks, 12 Latin American countries, 1999–2013
Source: Figure 1 in Moubarac 2014 (based on Euromonitor Passport
Global Market Information Database (2014) and WHO Global
Burden of Disease)
Note: Ultra-processed food and drink products include: carbonated drinks,
fruit and vegetable juices, ‘sports’ and ‘energy’ drinks, breakfast cereals,
sweet and savoury snacks, confectionery, ice creams, biscuits, spreads,
sauces and ready meals. Quantity in litres was converted into kilograms.
Figure 3.14: Consumption of soft drinks per person per day, USA, UK, Mexico, Brazil, Korea and China, 2008
2.8
1.6
3.7
1.0 0.8
0.4
1.3
0.7
1.2
0.7
0.2 0.1 0
0.5
1
1.5
2
2.5
3
3.5
4
US UK Mexico Brazil Korea, Rep China
Cups
per
per
son
per d
ay
Soft drinks
Of which, carbonates
Source: Constructed from USDA data and population estimates from
FAOSTAT. Original source: Euromonitor 2009
38 ODI Report
The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 39
3.7.3 Food and drink taxes in MexicoInDecember2013,aftermuchdebate,thelegislatureinMexicoapprovedtwotaxes:apeso(aboutUS$0.07)perlitreonsugarydrinksanda5%taxonenergy-densefoodswithmorethan275kcalper100grams(seeBox2Aforanillustrationoffoodsabovethisthreshold).
ThetaxonSSBsalonecouldhelpprevent515,000newcasesofdiabetesby2030andleadtoUS$14billioninsavingsforthehealthsystem(ArantxaColchero,NationalInstituteofPublicHealth,reportedinMartinandCattan(2013)).
EarlyreportssuggestthetaxmaybehelpingtostempurchasesofsomeSSBsandsnackfoods.AccordingtotheNationalObesitySurveyof1,500adultsinMexicoinAugust2014,52%ofMexicansreducedintakeofSSBsin2014(EFE2014).Moreover,‘some98percentofrespondentssaidconsumingsoftdrinkscontributedtoobesityandcausedpeopletogetdiseaseslikediabetes,thesurvey’.PepsiCosnacksalesvolumedroppedby3%,whileCoca-Colaalsoreportedadeclineinsalesoverthefirsthalfof2014–thoughMexicostillhastheworld’shighestconsumptionofCoca-Colapercapita(RT.com2014).
3.8 Summary of literature from emerging economies
• Somereportslinkchangesindiets,aboveallthoseinvolvingmoreconsumptionofprocessedfoods,toprocessedfoodandcookingoilbecomingcheaperthanotherfoods.
• InLatinAmerica,therisingconsumptionultra-processedfoodsandSSBsiscomingunderthespotlight.Someseethisconsumptionastheconsequenceofheavymarketingbythelargecorporationsthatmanufacturemuchofthisfoodanddrink.
• ThepossibilityofusingtaxestoreduceconsumptionofprocessedfoodandSSBsisactivelybeingstudied,withmostauthorsseeingthepotentialtosignificantlyreduceconsumption.MexicohasintroducedtaxesonbothSSBsandenergy-densefood.These,whichcameintoeffectinJanuary2014,willbethefocusofintensescrutinytoseewhateffectstheyhave.
4. Data and methods
The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 41
Keydataforthisreportareseriesforfoodpricesfrom1990torecentyears.Theaimwastocompilecomparableseriesofretailpricesforrepresentativefoodsacrossasampleofcountriesovertimefromatleast1990onwards,andwherepossiblefrom1980.Retail prices were sought for representative foods fromthefoodgroupssetoutinSection2,namely:staples,fruitsandvegetables;meat,seafood,anddairy;oils,fats,andsugar;andhighlyprocessedfoods.
Table4.1liststhefoodschoseninthefourcountriesplustheUK.Theaimwastoselectatleastonerepresentativefromeachfoodgroup,preferablyonewithlargeconsumption,and–otherthanfortheitemsintheprocessedcategory–foodsthatwereminimallyprocessedifatall.Inpractice,choicewaslimitedtotherangeofpriceseriesalreadycollectedineachcountry.Insomecountries,mostnotablyChina,priceswereavailableonlyforgroups
offoods,suchas‘cake,biscuitandbread’ratherthantheindividualproducts.
Ideallywewouldhavelikedtohavetheretailpricesforthesamefoodsacrossthefourcountries,butpublisheddatadidnotallowthat.Inanycase,theaimwastohaveatleastonefoodfromeachfoodgroup,choosingthosethataremosttypicallyconsumed.Sincedietsvarybycountry,relevantfoodsalsodiffer:forexample,thestaplefoodinKoreaisrice,whileinMexicoitismaize.
Justonepriceforeachfoodhasbeenused,eithernationalaveragesorthepricespaidinamajorcity.Itwasnotpossibletoobtainmoredetailonhowpricesvarywithincountriesbetween,forexample,urbanandruralareas,orbyfood.
Forthefourcountrystudies,throughourcollaborativegroup,dataweretakenfrompubliclyavailabledatabases,assetoutinTable4.2.
Table 4.1: Food prices analysed for each food group and country
Brazil China Korea, Rep Mexico UK
Staple Rice Grain Rice Tortillaandmaizeflour Flour(wheat)
Fruit or vegetables OrangesTomatoes Vegetables Dried and fresh fruits
Cabbage Tomato Freshvegetables
Freshgreenvegetables
Fats or sugar Sugar Soyoil
Oilandfat Vegetableoil Sugar
Oilsandediblefats Sugar
Sugar
Meat or dairy Beef Meat,poultryandproducts
Fish Chicken
Chicken Chicken
Highly processed Regularsausage Sweetbiscuit
Cake,biscuitandbread Ramen(noodles) Chocolateandsnacks Readymeals
Icecreamtub/block
Table 4.2: Data sources and deflators used for country cases
Country Deflator Data source
Brazil CPI • FoodpricedatacollectedbytheInstitutodeEconomiaAgrícola(InstituteofAgriculturalEconomics)ofSãoPauloStateforthemetropolitanareaofSãoPaulo,Brazil’slargestcity[2010populationof12.5millioninthemunicipality–themetropolitanareacontainsmore],from1980to2009.
• CPIdatafromFundaçãoInstitutodePesquisasEconômicas/UniversidadedeSãoPaulo,from1980to2009.Owingtohyper-inflationinthe1980sandearly1990s,significantcurrencychangestookplaceinMarch1986,January1989,August1993andJuly1994andhenceappropriatecorrectionshadtobemadetocomparepricesacrosscurrencyregimes,usinginformationfromFundaçãoInstitutodePesquisasEconômicas/UniversidadedeSãoPaulo(InstituteofEconomicResearch/UniversityofSãoPaulo).
China GDP • FoodpricedatafromChinaHealthandNutritionSurvey,andfoodpriceindexdatafromChinaStatisticalYearbooks.• GDPdeflatorfromIMF
Korea,Republic
CPI • FoodpriceindexdatafromtheConsumerPriceIndexforKorea(StatisticsKorea).Price-leveldatafromthemonthlyReportofCostofLivinginKoreaforJanuary2006.
• CPIdeflatorfromStatisticsKorea.CPIbyItem(Commodities&Services) http://kosis.kr/statHtml/statHtml.do?orgId=101&tblId=DT_1J0A112&conn_path=I3
Mexico CPI • FoodpriceindexdatafromINEGI(Mexico).Price-leveldataforMexicoCityfromProcuraduríaFederaldelConsumidor(Mexico)• CPIdeflatorfromWorldBankWDI
UK GDP • Unitfoodpricedata(nationalaverage)imputedfromsurveydataonspendingandconsumptionfromtheAdjustedNationalFoodSurveydata1974to2000,ExpenditureandFoodSurvey2001–02to2007andLivingCostsandFoodSurvey2008onwards.
• GDPdeflatorfromWorldBankWDI
Inmostcases,directlyobservedretailpriceswereused.ForMexico,however,afoodpriceindexwasusedandcalibratedtopricelevelsfromobservedpricesinMexicoCity.IntheUK,householdsurveysreportedbothspendingandquantityfor330foods.Henceitwaspossibletocreateunitpricesbydividingspendingbythequantity.Arguablythisproducesabettermeasureofprice,sinceunitpricescapturetheeffectsofthefrequentpricepromotionsseeninUKfoodretailing,andnotjusttherecommendedprice.
PriceserieshavebeendeflatedbyeithertheCPIortheGDPdeflatortoremovetheeffectofinflationandallowcomparisonovertime.Insomecases,suchastheUK,theCPIandtheGDPgivealmostidenticalresults.Inthreecases,however,theGDPdeflatorissignificantlystrongerthantheCPI:between1990and2012theGDPdeflatorexceededtheCPIaccountofinflationby21%for
China,by25%forMexico,andby59%forBrazil.Thosedifferencesmakenodifferencetocomparisonofchangesinrelativepriceswithincountry,butclearlyaffectcross-countrycomparisons,oraninterpretationofcomparablepricelevelsovertime.
Oncepricesweredeflated,indicesofthesesdeflatedpriceswereconstructedtoseehowmuchpricesofdifferentfoodsineachcountryhadchangedovertimefromthesamebaseyear.
Moreformaltestingofpricechangeswascarriedoutbyregressingtimeondeflatedandloggedpricesfrom1990toarecentyear,inmostcases2012.Thatallowedatestofwhetherasignificant(log-linear)trendcanbeinferred,andifso,whattheaverageannualpricechangehasbeen.Thekeyfindingsfromtheanalysisherecomefromtheseestimatedannualpricechanges.
42 ODI Report
5. Results of analysis: price movements
ThissectionreportswhatthedatashowforthefouremergingeconomiesandtheUK,thencomparestheseinsightstoderivebroaderinsights.AnnexIIIhasmoredetailsforeachofthecountries.Foreachcountry,pricesarepresentedintwoways.One,asconstantpricesperunitweight.Two,asindicesofthesepriceswithabasesettotheearly1980s;exceptforChinawherethemid-1990shadtobeusedsincetheseriesfortheonlyprocessedfoodinthesamplebeganthen,andforKoreawhereitwaspossibletotaketheindexbacktothelate1970s.Graphsofindicesmakeiteasiertocomparethesizeofchangesbetweenfoodswhentheyhaveverydifferentabsolutecostsperunitweight.
5.1 BrazilPricesofkeyfoodsinSãoPaulofrom1980to2009appearinFigure5.1,firstinconstant2009values,secondinconstantvaluesbutindexedtoacommon1980/82base.
Brazilianpricesarequitevolatileovertime,especiallyduringthe1980s.Inpartthesharpmovementsinpricesreflecttimesofhighinflationthatendedonlyinthemid-1990s.Despitethevariance,sometrendscanbeseen.Pricesoffruitandvegetables16havegainedthemost.Thelowestincreasesseenwereforrice,sausageandsoyoil.Sweetbiscuits,whichalongwithsausageareaprocessedfood,alsogainedquitealot.
Figure 5.1: Price of selected foods, São Paulo, Brazil, 1980–2009
(a) Constant 2009 prices
(b) Price indices, 1980/82 = 100
80
100
120
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160
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240
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Inde
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1982
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0
Tomato Orange Sweet biscuit
Beef Sugar Rice
Soy oil Regular sausage
Source: Data from Rafael Claro (Original source: data collected by the Instituto de Economia Agrícola (Institute of Agricultural Economics) of
São Paulo State for the metropolitan area of São Paulo, deflated to 2009 levels with CPI data and corrected for currency changes.
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The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 45
Allpricesriseintheseseries.Thatmaypartlyreflectthechoiceofdeflator,takenastheCPI.HadtheGDPdeflatorbeenused,somepriceswouldhavefallen,becauseitregistersafull60%moreinflationbetween1990and2012thantheCPI.Whilethisaffectsthestrengthoftrends,itdoesnotaffecttherelativechangesinpricesbetweenfoods.
5.2 ChinaPricesofselectedfoodsinChinafrom1989to2006appearinFigure5.2,firstinconstant2006values,secondinconstantvaluesbutindexedtoacommon1993base.
FoodpricesinChinahavebeennotablylessvariablefromyeartoyearthaninBrazil.Since1993,thepricesofriceandvegetableshaverisen;thoseforcake,biscuitandbreadhaveremainedalmostthesame;whilethoseforchicken,oilsandsugarhavefallen.
16 Orangesandtomatoeswerechosenasthesewerethemostcommonlyconsumedofthefruitandvegetablesintermsofgramspercapitainarecentconsumptionsurvey(datafromRafaelClaro).
Figure 5.2: Price of selected foods, China, urban areas, 1989–2006
(a) Constant 2006 prices
0
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Yuan
per
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Yuan
per
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Sugar Oils
Chicken Cake, biscuit, bread
Rice - R axis Vegetables (commonly eaten) - R axis
(b) Price indices, urban China 1984–2012, 1994/96 = 100
405060708090
100110120130140150160170
Inde
x (1
994
to 1
996
= 1
00)
Grain Oil and fat
Meat, Poultry and its products Vegetables
Dried and Fresh Fruits Cake, biscuit and bread
Source: Data from Satoru Shimokawa, based on China Statistical Yearbooks. Indices were adjusted to constant 2012 levels by China’s GDP
deflator from the IMF.
5.3 Republic of KoreaPricesofselectedfoodsinKoreafrom1975to2013appearinFigure5.3,firstinconstant2006values,secondinconstantvaluesbutindexedtoacommon1975–77base.
Onlytwooftheselectedfoodsroseinconstantpricefrom1975–77:fish,themostconsumedanimalproduct,17byalmostfourtimes,andcabbage–thekeyingredientofkimchi,Korea’snationaldish,by60%.Allotherfoodsbecamecheaper,aboveallsugarandvegetableoil.
17 In2011,averagepercapitasupplyofdemersalandpelagicfishintheRepublicofKoreawasaround37kg/capita.Incomparison,around16kg/capitaofpoultrymeatwassupplied(FAOSTAT).
Figure 5.3: Prices of selected foods, Republic of Korea, 1975–2013
(a) Constant 2006 prices
2007
2008
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2010
2011
2012
2013
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Kore
an W
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Rice Ramen Fish Chicken
Cabbage Vegetable oil Sugar
(b) Prices indexed to 1975/77=100
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Dried rice Ramen Chicken Cabbage
Vegetable oil Sugar Fish - R axis
Source: Data from Euna Han based on the Monthly Report of Cost of Living in Korea for January 2006 and the CPI for individual food items
between 1975 and 2013, deflated to 2006 values using the CPI.
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The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 47
5.4 MexicoPricesofkeyfoodsinMexicofrom1980to2014appearinFigure5.4,firstinconstant2010values,secondinconstantvaluesbutindexedtoacommon1980–82base.
Despiteconsiderableshort-termvariabilityinfoodprices,significanttrendscanbeseen.Somefoodcostshaverisensignificantly.By2014,maizeflourandtortillacostalmosttwicewhattheydidintheearly1980s.Policy
changeexplainsmuchofthissinceuntil1998tortillapriceswerecontrolled.AsFigure5.4shows,beforethatyear,priceshadnotrisensincetheearly1980sbutoncepriceswereliberalised,theydoubledwithinadecade.Tomatoesandotherfreshvegetablesalsoroseincost.Significantfallsinpricebyaround40%canbeseenforchicken,oilsandfats.Readymeals,chocolateandsnackshaveseensmallerpricesfalls.Sugarpriceshavebarelychanged.
Figure 5.4: Prices of selected foods, Mexico, 1980–2014
(a) Constant 2010 prices
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Peso
s pe
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s pe
r kg
Tortilla and maize flour Oils and edible fats
Tomato Chicken
Fresh vegetables Chocolate and snacks - R axis
(b) Priced indexed to 1980–82=100
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Inde
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Tortilla and maize flour Chocolate and snacks Ready meals
Oils and edible fats Tomato Fresh vegetables
Chicken Sugar
Source: Data from Joel Alberto Vargas Hernández, deflated by Mexican CPI from World Bank WDI. Original data on price indices for selected
foods for Mexico from INEGI Mexico, combined with data on actual food prices for 2015 from Mexico City (Procuraduría Federal del
Consumidor (México), accessed 25 February 2015.
Note: Food price series were constructed using national average price indices and price levels in early 2015 for Mexico City – these were
assumed as 2014 price levels for the purposes of simplicity. Resulting price trends indicate prices rather than actual observed prices.
5.5 United KingdomPricesofselectedfoodsintheUKfrom1974to2012appearinFigure5.5,firstinconstant2005–06values,thenaspriceindices;followedbyindicesforfoodgroups,weightedaccordingtorelativeweightofconsumption,indexedtoacommon1984–86base.
Panels(a)and(b)showthatthepriceoffreshgreenvegetableshasbeenrisinginconstanttermssincethe
1980s,whilethatoficecreamhasfallensignificantly.Pricesfortheotherthreeproductssawonlysmallchanges.
Forthefoodgroupsinpanel(c),pricesofstapleshaveriseninconstanttermsby50%sincethe1980s–largelyduetotherisingcostofpotatoes–whilethoseoffruitandvegetableshaverisenby30%.Pricesforfatsandsugarshavecomedownslightly;whilethoseformeatanddairyandprocessedfoodshavefallenby25%sincethe1980s.
Figure 5.5: Prices of selected foods, United Kingdom, 1974–2012
(a) Constant 2010 prices (b) Prices indexed to 1984–86=100
0
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150
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300
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1977
1980
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2010
Penc
e pe
r 100
g Flour
Ice cream tub/block
Sugar
Fresh green vegetables
Chicken
(c) Prices by food group, weighted and indexed to 1984–86=100
50
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Staples Processed Fats, sugars
Fruits and vegetables Meat and dairy
Source: Constructed from data from DEFRA
Note: Staples index includes flour, fresh potatoes, dried rice, and oatmeal/oat products. Processed index includes ice cream tub/block, chocolate
biscuits, chips (frozen or not), and ready meals and convenience meat. Fats and sugars index includes butter, vegetable oils excluding olive oil,
and sugar. Fruits and vegetables index includes fresh green vegetables, fresh onions (including leeks and shallots), fresh tomatoes, oranges and
bananas. Meat and dairy index includes eggs, chicken (uncooked, whole or in pieces), and whole milk.
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The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 49
5.6 Comparative analysisTocompareacrossthefivecountries,priceshavebeenanalysedfor1990to2012asfaraspossible:forChina,twofoodseriesbeginonlyin1993,whilealltheBrazilianpriceseriesendin2009.Forthisperiodasimpleregressionoftimeonloggedprices–itmakeslittledifferenceifthe
pricesarenotlogged–wascarriedout.Thisallowedtheseriestobecheckedtoseeiftherewasindeedasignificanttrendthroughtime,orwhetherthevariationsseenwerestochastic.Italsoallowedanestimatetobemadeofthedirectionandmagnitudeofthetrendinprices,averagedasalog-linearrelation.Table5.1setsouttheresults.
Table 5.1: Results of log-linear regression of time on prices
Country Product Period R-square F-stat Sig Slope t-stat
BRA Rice 1990-2009 0.39 11.39 0.0034 1.64% 3.37
BRA Sugar 1990-2009 0.00 0.07 0.8001 -0.15% -0.26
BRA Soyoil 1990-2009 0.56 22.55 0.0002 1.70% 4.75
BRA Beef 1990-2009 0.75 54.75 < 0.0001 1.86% 7.40
BRA Regularsausage 1990-2009 0.01 0.11 0.7474 0.07% 0.33
BRA Sweetbiscuit 1990-2009 0.54 20.94 0.0002 1.28% 4.58
BRA Tomato 1990-2009 0.87 122.82 < 0.0001 2.31% 11.08
BRA Orange 1990-2009 0.83 88.70 < 0.0001 2.51% 9.42
CHN Grain 1990-2012 0.37 12.49 0.0020 1.85% 3.53
CHN Oilandfat 1990-2012 0.11 2.64 0.1192 -0.51% -1.62
CHN Meat,Poultry&products 1990-2012 0.55 25.80 < 0.0001 1.30% 5.08
CHN Vegetables 1990-2012 0.94 319.45 < 0.0001 2.98% 17.87
CHN DriedandFreshFruits 1993-2012 0.08 1.51 0.2357 0.39% 1.23
CHN Cake,biscuitandbread 1993-2012 0.26 6.29 0.0219 -0.67% -2.51
KOR Dried rice 1990-2012 0.49 19.99 0.0002 -1.02% -4.47
KOR Ramen 1990-2012 0.92 254.11 < 0.0001 1.46% 15.94
KOR Chicken 1990-2012 0.04 0.92 0.3481 0.26% 0.96
KOR Fish 1990-2012 0.70 49.64 < 0.0001 1.83% 7.05
KOR Cabbage 1990-2012 0.85 114.55 < 0.0001 3.04% 10.70
KOR Vegetableoil 1990-2012 0.33 10.36 0.0041 1.06% 3.22
KOR Sugar 1990-2012 0.12 2.98 0.0988 0.57% 1.73
MEX Tortillaandmaizeflour 1990-2012 0.90 196.30 < 0.0001 3.73% 14.01
MEX Chocolateandsnacks 1990-2012 0.21 5.68 0.0266 -0.32% -2.38
MEX Readymeals 1990-2012 0.21 5.62 0.0274 -0.84% -2.37
MEX Oilsandediblefats 1990-2012 0.00 0.04 0.8408 -0.09% - 0.20
MEX Tomato 1990-2012 0.64 37.59 < 0.0001 2.04% 6.13
MEX Freshvegetables 1990-2012 0.77 69.61 < 0.0001 1.13% 8.34
MEX Chicken 1990-2012 0.54 24.66 < 0.0001 -1.79% -4.97
MEX Sugar 1990-2012 0.52 22.84 0.0001 1.39% 4.78
UK Flour 1990-2012 0.16 3.97 0.0594 0.65% 1.99
UK Icecreamtub/block 1990-2012 0.79 78.22 < 0.0001 -3.31% - 8.84
UK Sugar 1990-2012 0.01 0.25 0.6209 -0.13% -0.50
UK Freshgreenvegetables 1990-2012 0.97 694.18 < 0.0001 3.26% 26.35
UK Chicken 1990-2012 0.71 51.73 < 0.0001 0.71% 7.19
Source: Regressions of time on logged prices. Data from sources in Section 4.
Note: Cells in grey are insignificant estimates. Cells in italics are marginally significant estimates. Slope estimates expressed as percentages.
Nineofthe34estimates(showningreyinTable5.1)werenotsignificantatthe5%level,whileanotherthree(showninitalics)werenotsignificantatthe1%level.Removingthenineinsignificantestimatesandrearrangingthestatisticsbyfoodgroup,presentingtheslopeestimatesinachartgivesFigure5.6.
Twothingsarereadilyapparent.Oneisthatpricesoffruitandvegetableshaverisensubstantiallysince1990,mainlybybetween2%and3%ayearonaverage–orby55–91%between1990and2012.Theotheristhatfourofthesixprocessedproductsforwhichestimatesaresignificantshowpricefallssince1990.18Mostoftheotherfoodshaveseentheirpricesriseby1–2%ayear,withtheexceptionsofthepricefallsseenforriceinKoreaandchickeninMexico.
Figure 5.6: Estimated average annual price change from 1990
-4 -3 -2 -1 0 1 2 3 4
GrainDried rice
RiceTortilla and maize flour
Vegetable oilSoy oilSugar
Meat, Poultry and its productsFishBeef
ChickenChicken
VegetablesTomatoOrange
CabbageTomato
Fresh vegetablesFresh green vegetables
Cake, biscuit and breadRamen
Sweet biscuitChocolate and snacks
Ready mealsIce cream tub/block
CHKR
BRM
XKR
BRM
XCH
KRBR
MX
UKCH
BRBR
KRM
XM
XUK
CHKR
BRM
XM
XUK
Staples
Oil and sugar
Meat, poultry, fish
Fruit & vegetables
Processed foods
Source: Table 5.1
18 WhileramenpriceshaveriseninKoreasincetheearly1990s,theyhadfallenconsiderablyfromthemid-1970sto1991,sothatby2013theywerestillcheaperthan40yearsago.
50 ODI Report
6. Conclusion and discussion
6.1 Changing pricesThesinglemoststrikingfindingisthatinemergingeconomiesthepricesoffruitandvegetableshaverisensince1990(andinsomecasesforlongerthanthat)andmorerapidlythanthoseofmostotherfoods.ThisreplicateswhatcanbeseenforbothUSAandUKpricesoffruitandvegetables.
Limitedevidencealsosuggeststhatpricesofprocessedfoodshaveeitherfallenorhaveincreasedslowlyintheemergingeconomies,aresultthatagainreflectswhatcanbeseenfortheUSAandtheUK.
Twoqualificationsapply,however.First,pricetrendsseenareuneven,varyingovertime,betweencountriesandbetweensimilarfoodswithincountries.Whiletrendscanbeseen,otherfactorsmustbeatwork–includingthedisconcertingpossibilitythatpricesarenotcarefullyobservedandreported.
Second,thequalityandnatureoftheobservedfoodsmaychangeovertime,apointwelldocumentedfortheUSAwheremostfruitandvegetableshavemoreaddedvalueonthesupermarketshelfthantheyhad30ormoreyearsago–cutandtrimmed,bagged,washed,andavailableallyearround,nomatterwhattheseason.Mightthisalsobethecaseintheemergingeconomies?Thiswouldrequiremorestudy.
Ifthetrendsdetectedarereal,somethingotherthanillusionsseeninnoisydatadistortedbyhedonicchanges,theypromptquestionsaboutthereasonsforthem.If,forexample,technicalprogressinfarmingwereuniformsothatunitcostsofproductionwerefallingforallagriculturaloutput,andifadvancesinthelogisticsoffoodwholesalingandretailingweresimilarlyuniform,thenwemightexpectthecostsofmostfoodstomoveroughlyinlinewithoneanother.Butthatisnotthecase.
Sowhyhavefruitandvegetablesbecomemorecostlycomparedtootheritems?Itisnotasthoughtherehavenotbeentechnicaladvancesinhorticulture:onthecontrarysomeofthemostsophisticatedseeds,soilnutrition,watercontrol,andpreventionofpestsanddiseasesareseenpreciselyinthegardensandglasshousesinwhichsomanyfruitandvegetablesaregro.WhilethereisaworldofdifferencebetweenDutchheatedglasshousesandthetinyplotsofgreenbeansofcentralKenya,inbothcases,comparedtootheragricultureintheirneighbourhoods,thesesystemsarebothmoreintensiveandusemoresophisticatedtechnologythanmostotherlocalfarmenterprises.Moreover,advancesintransportmeanthatfruitandvegetablesaretradedmorethaninthepast,sothatretailmanagersshouldbeabletosourcefromlow-costsuppliersnomatterwheretheymaybe.
Hypothesescanbeimagined:horticulturemaywellhaveasteppedsupplyfunction,sothatwhilesmallquantitiesoffruitandvegetablescanbesuppliedatlowunitcost,onceaparticularvolumeisreached,costsrapidlyescalatetoasignificantlyhigherlevel.Itmayalsobethatthechangesinqualitynotedexplaintheincreasedrelativeprices.Or,it
maynotbeamatterofcostbutofincreaseddemandfromthoseconsumerswhoappreciatethehealthbenefitsoffruitandvegetables.Thesehypothesesmeritaseparatestudy.
Whydoesnotthesameapplytosomeprocessedfoods?Onepossibilityisthatmuchprocessedfooddoesnotrelyoncostlyfarmingredients,butratherismanufacturedfromrelativelycheapingredients,theaddedvaluebeinglargelyinfactoryprocessesofcombiningtheingredientsandenhancingtheirflavour.Advancesinmanufacturingandflavouringprobablyhelpreduceunitcostsinfactory.Thatsaid,processedfoodsarenotuniforminqualityandpricing,sinceforanysub-category,thereareusuallyproductsthatarebranded,soldontheirspecialcharacteristics,usuallywithapricepremium–asapplies,forexample,tosoftdrinksthatcompetewithcheaper,unbrandedoptions.ThismayexplainwhynotalltheprocessedfoodsconsideredinTable5.8showdecliningconstantprices.Onceagain,additionalstudiesmightshedlightonthis.
6.2 Do prices matter … and might taxes work?
Evidencepresentedintheliteraturereviewsuggeststhatpricesdoaffectconsumption,especiallyforpeopleonlowincomes.Own-priceelasticityofdemandforfoodmayberelativelyinelastic,butnotthatinelastic–USestimatesofown-priceelasticityformostfoodsareabove(minus)0.45.Hencepricechangesdoinfluencediets.Moreover,itisstrikingtoseethatintheUSA,wheremanyconsumerscanaffordmostfoodtheywish,consumptionissensitivetoprice,especiallyforSSBs–presumablybecausethereareplentyofalternativesoftdrinksifonebecomesmoreexpensivethantherest.
Henceitisnosurprisetoseemuchstudyofthepotentialoftaxesonlesshealthyoptionstoreducetheirconsumption,perhapsevenwithsubsidiesonmorehealthyoptionstoraisetheirs.Mostsuchstudiesindicatethatimposingtaxeswouldreduceconsumption.Buttwoqualificationsapply.
Oneisthattheremaybecross-priceeffects,wherebywhentaxesraisethecostofaparticularfood,notonlydoesitsconsumptionfall,butsotoodoesthatofcomplements(foodswhicharetypicallyconsumedtogether,suchasbreadandbutter).Whenthosecomplementscontainvaluednutrientsitisthuspossiblefortaxestoreducethequalityofdiet.Intheorythisproblemcanreadilybetackledbyplacingasubsidyonthevaluedcomplementtooffsetthecross-priceeffect.Inpractice,learningwhichfoodsreallyarecomplements,towhatextent,andthendetermininganoptimallevelofsubsidy,couldleadtoathicketofregulationsthathavetobeadjustedinthelightofemergingevidence,creatinghighadministrativecostsandgivingtheimpressionthatsuchfiscalmeasuresarejusttoodifficulttocontemplate.Thequestionishowstrongcross-priceeffectsareandwhethertheymayberemediedbyothermeasurestoencouragehealthierdiets.
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The rising cost of a healthy diet: Changing relative prices of foods in high-income and emerging economies 53
Thesecondistheapparentlyseductiveargumentthatsmalltaxeswouldcreateonlysmalleffects:thatconsiderablechangeinconsumptionwouldrequirehightaxesthatwouldlookdisproportionateandunfair–say,morethantherateofVATof20%intheUKcase.Butalogicalflawapplieshere.Thepolicyquestionisnotsomuch,‘howlargeataxwouldbenecessarytobringdownconsumptionoflesshealthyfoodXtorecommendedorinsignificantlevels’,but‘howmuchbenefitwouldbederivedfromimposingapoliticallyacceptabletaxonlesshealthyfoodX?’Theanswertotheformerquestionmaybeanumbersohighastobedismissedfromthedebate;buttheanswertothelatterquestionmaybeasstrikingasthatprovidedbyNnoahametal.(2009)fortheUK:thattaxesandsubsidiesoflessthan20%couldsavenofewerthan6,400prematuredeathsayearfromcoronaryheartdiseaseandcancers.If6,400peopleweretodieinacatastrophicaccident,massiveresourceswouldbedeployed
topreventarepetition.RoaddeathsintheUKarefarfewerthanthisnumber(lessthan2,000ayear),toavoidwhichallmannerofregulationsapplytoroadusers.Theargumentaboutsmalltaxes,smallgainsistantamounttoargumentsthatcondemndoinggoodbecauseperfectionisunattainable–‘le mieux est l’ennemi du bien’,asVoltaireputit.
Intermsofwhatmightbetaxedandsubsidised,thisreportsuggeststhatenergy-densefoodsmightbetaxed,whilefruitandvegetableswhosepricesoftenrisecomparedtootherfoods,mightbesubsidised.
Muchcomesdowntothepoliticalappetitetocontemplatetaxingfoods(seeBox6A).EventsinMexicosuggestthatsomeemergingeconomiesmaystealamarchonHICsinthisrespect.TheevidencepresentedinthisreportsuggeststhattheMexicantaxesshoulddoconsiderablegood,therebyprovidingvaluablelessonsforotherdevelopingandemergingeconomies.
Box 6A: How feasible are taxes on foods?
Sugar,rum,andtobacco,arecommoditieswhicharenowherenecessariesoflife,whicharebecomeobjectsofalmostuniversalconsumption,andwhicharethereforeextremelypropersubjectsoftaxation.AdamSmith, The Wealth of Nations
InboththeUSAandtheUK,althoughratesofoverweightandobesityhavelongbeenrecognisedinhealthcarecirclesashavingreachedepidemicproportions,policy-makershavebeenslowtorecognisetheseverityoftheissue.LangandRayner(2007)suggestedthismaystemfromsloworineffectiveadvocacyworkbypublichealthproponents;fromevidencethatisnoteasilytranslatedintopolicy;orfromalackofpoliticalchampions.Someofthesefactorsarechanging,thoughprogressisslow.IntheUSAinparticularpoliticalchampionshaveemergedinrecentyears:MichelleObama’scampaignagainstchildobesity‘Let’sMove’waslaunchedin2010,alongsidetherelatedPartnershipforaHealthierAmerica(PHA);19whilethethenmayorofNewYork,MichaelBloomberg,attempted,unsuccessfully,20togettougherregulationsonthesizeoffizzydrinktotakeeffectin2013.ChampionsarelessvisibleintheUK,mostofthosebeingcelebritycookssuchasJamieOliverratherthanpoliticians.Byandlarge,economicmeasurestocontrolobesityarenotcommoninfooddebatesintheUK:
…beyondthewidelydebatedfoodtaxes,theuseoffinancialmechanismstoencouragehealthierdietshasnotbeenavisiblepartofthepolicydebateabouthealthyeatingandobesityintheUnitedKingdom.(Hawkes2009b)
TowhichLangandRayner(2009)add:
ThereisapowerfultemptationinGovernmenttolimitactionstoachoice-based,personalizationapproach,inpartbecausethisstyleofinterventionisalignedtothecommercialsector’sowncustomermanagementandmarketingmethods,butalsobecauseacross-societyapproachappearssobiginconceptionthatfailureisassumed.
Yetthismaybechanging:
Oncedispatchedtothebottomdrawofpolicyoptionstoaddressunhealthyeating,foodtaxesnowseembackintheouttrayofEuropeanpolicymakers.EvenDavidCameronmadeanoffhandquiprecentlysuggestingthatthisissomethingtheBritishGovernmentmightexplore.(Hawkes2012)
IntheUSAtheDietaryGuidelinesAdvisoryCommittee’sreporttotheSecretaryofHealthandHumanServicesandtheSecretaryofAgriculture(USDA,2015)hasjustbeenreleased,whichrecommendstaxandtax-subsidypolicies:
AlignnutritionalandagriculturalpolicieswithDietaryGuidelinesrecommendationsandmakebroadpolicychangestotransformthefoodsystemsoastopromotepopulationhealth,including the use of economic and taxing policiestoencouragetheproductionandconsumptionofhealthyfoodsandtoreduceunhealthyfoods.Forexample,earmark tax revenues from sugar-sweetened beverages, snack foods and desserts high in calories, added sugars, or sodium, and other less healthy foods for nutrition education initiatives and obesity preventionprograms.(USDA2015;emphasisadded)
Althoughindustrylobbiesmaycampaignhardagainsttaxes–theAmericanBeverageAssociationspentUS$7.7millionopposingaproposedtaxonSSBsinSanFrancisco(Rt.com2014)–thepublicmaybemorebehindtax/subsidyinitiativesthanpoliticiansrealise.ApollofNewYorkresidentsfoundthat:
…52%supporteda‘sodatax,’butthenumberroseto72%whenrespondentsweretoldthattherevenuewouldbeusedforobesityprevention.(BrownellandFrieden2009)
MonteiroandCannon(2012)arguethattaxesmaybemoreacceptablesociallyandpoliticallyinBrazilandotherdevelopingcountries,comparedtosomeHICs:
‘…theviewsofmanycommentatorsandpolicy-makersintheSouthareinsharpcontrastwiththeircounterpartsintheNorth.IncountriesliketheUS,thegeneraltendencyistodealwithfood,nutrition,andpublichealthinisolationasmatterslargelyofinformation,education,and“individuallifestyleadjustments”designedtoreducetheriskofvariousdisabilitiesanddiseases.ButinBrazilandothercountriesintheSouth,foodisseenbymostindependentscholarsandpolicy-makersaspartofamuchbroaderdiscoursethatinvolvesgeneralwell-being,thefamily,friendship,commensality,culture,sustainablelivelihoods,environmentalpreservation,nationalidentityandsovereignty,aswellaspersonalandpublichealth.(MonteiroandCannon2012)
Theyarenotaloneinseeingthegovernmentsofemergingeconomiesasmorepreparedtoactforbetterhealth,asJames(2008)arguesforChina:
Chinahastraditionallybeenfarmoreresponsivetothevalueofpolicieswhichlimitinequalitiesandestablishstandardsofcarethanmanywesterngovernments,whohaveyettorecognizethattheindividualisticfree-marketapproachtoobesitypreventionisguaranteedtofail.Chinacouldthereforeleadtheway:ifitfollowswesternapproaches,thehealthandeconomicburdenwillbecomeunsustainable.
19 RecentinitiativeslinkedtothisincludethePHA’s(ForinfoonPHAseehttp://ahealthieramerica.org/about/about-the-partnership/)‘DrinkUp’campaign(seehttp://www.youarewhatyoudrink.org/about/)toencouragepeopletodrinkmorewater,andtheplannedFNV(FruitandVegetables–seehttp://www.fnv.com/)celebrity-backedmarketingcampaigntopromoteconsumptionofFNVasabrand,usingsophisticatedadvertisingtechniques.
20 Ultimatelythisplanfailed:seehttp://en.wikipedia.org/wiki/Sugary_Drinks_Portion_Cap_Rule/.
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