real sale prices vs. displayed prices : an issue to consider before expanding scanner data to other...
TRANSCRIPT
2015/10/01
Isabelle LEONARDProject manager for statistical issuesInsee
Real sale prices vs. displayed prices :an issue to consider before expanding scanner data to other sectors than food products French scanner data project
2015/10/01European scanner data workshop2
French scanner data project
Objective :Computing an index using scanner datafor industrial food products, health and beauty, and home care productssold in mass-market retail stores in métropolitan Francewithout changing the current concepts of the CPI
Laspeyres index, chained annualyBasket up-dated at the beginning of each yearWeight computed from the turnovers of the previous yearReplacements of products during the year with a quality-adjustment
2015/10/01European scanner data workshop3
The phases of a project at Insee
2015/10/01European scanner data workshop4
A first test in 2011
Goal : checking of the prices provided in the scanner data
Method :search for the products collected in outletsin a sample of scanner data (10 families of products sold in 1000 outlets)by teams in offices that compared the descriptions of the products in the collection and in scanner data
Results :
Number of products %
Identical prices 208 60
Prices difference < 5% 51 15
Prices difference > 5% or failure to find the product
86 25
Total 345 100
2015/10/01European scanner data workshop5
A second test in 2014
A new method to correct two problems in the first test :– Using the GTIN to identify products in the collection– Using daily scanner data prices (v.s. weekly average prices)
Aims of the 2nd test : – Is the GTIN a reliable identifier for items?– Are the prices in scanner data close to the prices in collection?
2015/10/01European scanner data workshop6
The management of the test
• When ?From the 2nd until the 27th of june 2014
• Where?in supermarkets and hypermarkets of metropolitan France(Only the stores of the firms that agree to send their scanner data to Insee)
• How?The barcodes of the items were scanned by price collectors at the same
time they collected the prices of all products of the CPI
2015/10/01European scanner data workshop7
The search for sales in scanner data
• 1021 barcodes scanned in 40 outlets
• Research for a salefrom the 5th of may until the 27th of julyindependently of the date of the collectionthe sale retained is closest to the date of the collection
2015/10/01European scanner data workshop8
Results of the test
Number of products %
Identical prices 829 81,3
Different prices 124 12,1
No sale 35 3,4
The barcodes don’t translate a GTIN 33 3,2
TOTAL 1021 100,0
2015/10/01European scanner data workshop9
Products not sold during the 3 months
SectorsNumber of
products not soldNumber of
products sold% of products
not sold
Food products 1 526 0,2
Manufactured goods 12 234 4,9
Clothing 13 128 9,2
Durables goods 9 65 12,2
Total 35 953 3,5
2015/10/01European scanner data workshop10
Period between the sale and the collection
sectors
% of products sold
Number of
matched barcodes
Max length
before the collection
Max length
after the collection
from8
until49
days
from1
until7
days
thesameday
from1
until7
days
from8
until49
days
before than after
the collection
Food products 1.1 8.6 80.4 9.3 0.6 526 23 14
Manufactured goods 10.3 21.4 36.8 23.1 8.5 234 43 37
Clothing 16.4 21.9 10.2 21.1 30.5 128 35 18
Durable goods 10.8 15.4 10.8 16.9 46.2 65 27 49Total 6,1 14,0 55,5 14,8 9.7 953
2015/10/01European scanner data workshop11
Différent dates, more different prices?
sector
Products soldthe same day another day
than the collection
Number of products
Number of products sold at
different prices
% Number of products
Number of products sold at
different prices
%
Food products 423 42 9,9 103 8 7,8Manufactured goods 86 5 5,8 148 13 8,9Clothing 13 5 38,5 115 34 29,6Durable goods 7 1 14,3 58 15 25,9Total 529 53 10,0 424 70 16,7
2015/10/01European scanner data workshop12
Results and limits
• Less sales in clothing and durables goods– Many days without sales of a precise product– For some items, no sales during a long period
but no evident consequences on prices
• The limits of the study– Few products in durable goods and clothing (215)– July (the month after the test) is a sales period in France– No specialised store in the sample of outlet
Thank you for your attention !
ContactIsabelle LéonardTél. : 01 41 17 68 05Courriel :[email protected]
Insee18 bd Adolphe-Pinard75675 Paris Cedex 14
www.insee.fr
Informations statistiques :www.insee.fr / Contacter l’Insee09 72 72 4000(coût d’un appel local)du lundi au vendredi de 9h00 à 17h00