velly economics 1 q ans

Upload: dany-kp

Post on 07-Apr-2018

237 views

Category:

Documents


0 download

TRANSCRIPT

  • 8/3/2019 Velly Economics 1 Q ANS

    1/13

    Registration for WikiConference India 2011, Mumbai is now open.Click here to

    register.

    Price elasticity of demandFrom Wikipedia, the free encyclopedia

    Not to be confused withPrice elasticity of supply.

    PED is derived from the percentage change in quantity (%Qd) and percentage change in price

    (%P).

    Price elasticity of demand (PED or Ed) is a measure used in economics to show the responsiveness,

    orelasticity, of the quantity demanded of a good or service to a change in its price. More precisely, it gives the

    percentage change in quantity demanded in response to a one percent change in price (holding constant all the

    other determinants of demand, such as income). It was devised byAlfred Marshall.

    Price elasticities are almost always negative, although analysts tend to ignore the sign even though this can

    lead to ambiguity. Only goods which do not conform to thelaw of demand, such asVeblenandGiffen goods,have a positive PED. In general, the demand for a good is said to be inelastic(or relatively inelastic) when the

    PED is less than one (in absolute value): that is, changes in price have a relatively small effect on the quantity

    of the good demanded. The demand for a good is said to be elastic(or relatively elastic) when its PED is

    greater than one (in absolute value): that is, changes in price have a relatively large effect on the quantity of a

    good demanded.

    http://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://en.wikipedia.org/wiki/Price_elasticity_of_supplyhttp://en.wikipedia.org/wiki/Price_elasticity_of_supplyhttp://en.wikipedia.org/wiki/Price_elasticity_of_supplyhttp://en.wikipedia.org/wiki/Elasticity_(economics)http://en.wikipedia.org/wiki/Elasticity_(economics)http://en.wikipedia.org/wiki/Elasticity_(economics)http://en.wikipedia.org/wiki/Alfred_Marshallhttp://en.wikipedia.org/wiki/Alfred_Marshallhttp://en.wikipedia.org/wiki/Alfred_Marshallhttp://en.wikipedia.org/wiki/Law_of_demandhttp://en.wikipedia.org/wiki/Law_of_demandhttp://en.wikipedia.org/wiki/Law_of_demandhttp://en.wikipedia.org/wiki/Veblen_goodhttp://en.wikipedia.org/wiki/Veblen_goodhttp://en.wikipedia.org/wiki/Veblen_goodhttp://en.wikipedia.org/wiki/Giffen_goodhttp://en.wikipedia.org/wiki/Giffen_goodhttp://en.wikipedia.org/wiki/Giffen_goodhttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand.svghttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand.svghttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://en.wikipedia.org/wiki/Price_elasticity_of_demandhttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand.svghttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand.svghttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://en.wikipedia.org/wiki/Price_elasticity_of_demandhttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand.svghttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand.svghttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://en.wikipedia.org/wiki/Price_elasticity_of_demandhttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand.svghttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand.svghttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://en.wikipedia.org/wiki/Price_elasticity_of_demandhttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand.svghttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand.svghttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://en.wikipedia.org/wiki/Price_elasticity_of_demandhttp://en.wikipedia.org/wiki/Giffen_goodhttp://en.wikipedia.org/wiki/Veblen_goodhttp://en.wikipedia.org/wiki/Law_of_demandhttp://en.wikipedia.org/wiki/Alfred_Marshallhttp://en.wikipedia.org/wiki/Elasticity_(economics)http://en.wikipedia.org/wiki/Price_elasticity_of_supplyhttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registrationhttp://meta.wikimedia.org/wiki/WikiConference_India_2011/Registration
  • 8/3/2019 Velly Economics 1 Q ANS

    2/13

    Revenue is maximised when price is set so that the PED is exactly one. The PED of a good can also be used

    to predict theincidence (or "burden") of a taxon that good. Various research methods are used to determine

    price elasticity, includingtest markets, analysis of historical sales data andconjoint analysis.

    Contents

    [hide]

    1 Definition

    o 1.1 Point-price elasticity

    o 1.2 Arc elasticity

    2 History

    3 Determinants

    4 Interpreting values of price elasticity coefficients

    5 Effect on total revenue

    6 Effect on tax incidence

    7 Selected price elasticities

    8 See also

    9 Notes

    10 References

    11 External links

    [edit]DefinitionPED is a measure of responsiveness of the quantity of a good or service demanded to changes in its

    price.[1]

    The formula for the coefficient of price elasticity of demand for a good is:[2][3][4]

    The above formula usually yields a negative value, due to the inverse nature

    of the relationship between price and quantity demanded, as described by the

    "law of demand".

    [3]

    For example, if the price increases by 5% and quantitydemanded decreases by 5%, then the elasticity at the initial price and quantity

    = 5%/5% = 1. The only classes of goods which have a PED of greater than

    0 areVeblenandGiffengoods.[5]

    Because the PED is negative for the vast

    majority of goods and services, however, economists often refer to price

    elasticity of demand as a positive value (i.e., inabsolute valueterms).[4]

    http://en.wikipedia.org/wiki/Incidence_of_taxhttp://en.wikipedia.org/wiki/Incidence_of_taxhttp://en.wikipedia.org/wiki/Incidence_of_taxhttp://en.wikipedia.org/wiki/Marketing_researchhttp://en.wikipedia.org/wiki/Marketing_researchhttp://en.wikipedia.org/wiki/Marketing_researchhttp://en.wikipedia.org/wiki/Conjoint_analysis_(in_marketing)http://en.wikipedia.org/wiki/Conjoint_analysis_(in_marketing)http://en.wikipedia.org/wiki/Conjoint_analysis_(in_marketing)http://en.wikipedia.org/wiki/Price_elasticity_of_demandhttp://en.wikipedia.org/wiki/Price_elasticity_of_demandhttp://en.wikipedia.org/wiki/Price_elasticity_of_demandhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Definitionhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Definitionhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Point-price_elasticityhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Point-price_elasticityhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Arc_elasticityhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Arc_elasticityhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Historyhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Historyhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Determinantshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Determinantshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Interpreting_values_of_price_elasticity_coefficientshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Interpreting_values_of_price_elasticity_coefficientshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Effect_on_total_revenuehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Effect_on_total_revenuehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Effect_on_tax_incidencehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Effect_on_tax_incidencehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Selected_price_elasticitieshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Selected_price_elasticitieshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#See_alsohttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#See_alsohttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Noteshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Noteshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Referenceshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Referenceshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#External_linkshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#External_linkshttp://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=1http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=1http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=1http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Png57-0http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Png57-0http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Png57-0http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-1http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-1http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie43-2http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie43-2http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie43-2http://en.wikipedia.org/wiki/Veblen_goodhttp://en.wikipedia.org/wiki/Veblen_goodhttp://en.wikipedia.org/wiki/Veblen_goodhttp://en.wikipedia.org/wiki/Giffen_goodhttp://en.wikipedia.org/wiki/Giffen_goodhttp://en.wikipedia.org/wiki/Giffen_goodhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie2007-4http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie2007-4http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie2007-4http://en.wikipedia.org/wiki/Absolute_valuehttp://en.wikipedia.org/wiki/Absolute_valuehttp://en.wikipedia.org/wiki/Absolute_valuehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Absolute_valuehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie2007-4http://en.wikipedia.org/wiki/Giffen_goodhttp://en.wikipedia.org/wiki/Veblen_goodhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie43-2http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-1http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-1http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Png57-0http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=1http://en.wikipedia.org/wiki/Price_elasticity_of_demand#External_linkshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Referenceshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Noteshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#See_alsohttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Selected_price_elasticitieshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Effect_on_tax_incidencehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Effect_on_total_revenuehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Interpreting_values_of_price_elasticity_coefficientshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Determinantshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Historyhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Arc_elasticityhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Point-price_elasticityhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#Definitionhttp://en.wikipedia.org/wiki/Price_elasticity_of_demandhttp://en.wikipedia.org/wiki/Conjoint_analysis_(in_marketing)http://en.wikipedia.org/wiki/Marketing_researchhttp://en.wikipedia.org/wiki/Incidence_of_tax
  • 8/3/2019 Velly Economics 1 Q ANS

    3/13

    This measure of elasticity is sometimes referred to as the own-priceelasticity

    of demand for a good, i.e., the elasticity of demand with respect to the good's

    own price, in order to distinguish it from the elasticity of demand for that good

    with respect to the change in the price of some other good, i.e.,

    acomplementaryorsubstitute good.[1]The latter type of elasticity measure is

    called across-price elasticity of demand.[6][7]

    As the difference between the two prices or quantities increases, the accuracy

    of the PED given by the formula above decreasesfor a combination of two

    reasons. First, the PED for a good is not necessarily constant; as explained

    below, PED can vary at different points along thedemand curve, due to its

    percentage nature.[8][9]

    Elasticity is not the same thing as theslopeof the

    demand curve, which is dependent on the units used for both price and

    quantity.[10][11]Second, percentage changes are not symmetric; instead,

    thepercentage changebetween any two values depends on which one is

    chosen as the starting value and which as the ending value. For example, if

    quantity demanded increases from10 units to15 units, the percentage

    change is 50%, i.e., (15 10) 10 (converted to a percentage). But if quantity

    demanded decreases from15 units to10 units, the percentage change is

    33.3%, i.e., (10 15) 15.[12][13]

    Two alternative elasticity measures avoid or minimise these shortcomings of

    the basic elasticity formula: point-price elasticityand arc elasticity.

    [edit]Point-price elasticity

    One way to avoid the accuracy problem described above is to minimise the

    difference between the starting and ending prices and quantities. This is the

    approach taken in the definition of point-priceelasticity, which usesdifferential

    calculusto calculate the elasticity for an infinitesimal change in price and

    quantity at any given point on the demand curve:[14]

    In other words, it is equal to the absolute value of the first derivative of

    quantity with respect to price (dQd/dP) multiplied by the point's price (P)

    divided by its quantity (Qd).[15]

    http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gwartney425-3http://en.wikipedia.org/wiki/Complementary_goodhttp://en.wikipedia.org/wiki/Complementary_goodhttp://en.wikipedia.org/wiki/Complementary_goodhttp://en.wikipedia.org/wiki/Substitute_goodhttp://en.wikipedia.org/wiki/Substitute_goodhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Png57-0http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Png57-0http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Png57-0http://en.wikipedia.org/wiki/Cross-price_elasticity_of_demandhttp://en.wikipedia.org/wiki/Cross-price_elasticity_of_demandhttp://en.wikipedia.org/wiki/Cross-price_elasticity_of_demandhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-5http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-5http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-5http://en.wikipedia.org/wiki/Demand_curvehttp://en.wikipedia.org/wiki/Demand_curvehttp://en.wikipedia.org/wiki/Demand_curvehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-7http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-7http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-7http://en.wikipedia.org/wiki/Slopehttp://en.wikipedia.org/wiki/Slopehttp://en.wikipedia.org/wiki/Slopehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Percentage#Percentage_increase_and_decreasehttp://en.wikipedia.org/wiki/Percentage#Percentage_increase_and_decreasehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ruffin-11http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ruffin-11http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ruffin-11http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=2http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=2http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=2http://en.wikipedia.org/wiki/Differential_calculushttp://en.wikipedia.org/wiki/Differential_calculushttp://en.wikipedia.org/wiki/Differential_calculushttp://en.wikipedia.org/wiki/Differential_calculushttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-sloman-13http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-sloman-13http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-sloman-13http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Wessels2000-14http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Wessels2000-14http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Wessels2000-14http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Wessels2000-14http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-sloman-13http://en.wikipedia.org/wiki/Differential_calculushttp://en.wikipedia.org/wiki/Differential_calculushttp://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=2http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ruffin-11http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ruffin-11http://en.wikipedia.org/wiki/Percentage#Percentage_increase_and_decreasehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Slopehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-7http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-7http://en.wikipedia.org/wiki/Demand_curvehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-5http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-5http://en.wikipedia.org/wiki/Cross-price_elasticity_of_demandhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Png57-0http://en.wikipedia.org/wiki/Substitute_goodhttp://en.wikipedia.org/wiki/Complementary_good
  • 8/3/2019 Velly Economics 1 Q ANS

    4/13

    In terms of partial-differential calculus, point-price elasticity of demand

    can be defined as follows:[16]

    let be the demand of

    goods as a function of parameters price and wealth,

    and let be the demand for good . The elasticity of demand

    for good with respect to pricepk is

    However, the point-price elasticity can be computed only if the

    formula for thedemand function,Qd = f(P), is known so its

    derivative with respect to price, dQd /dP, can be determined.

    [edit]Arc elasticity

    A second solution to the asymmetry problem of having a PED

    dependent on which of the two given points on a demand curve is

    chosen as the "original" point and which as the "new" one is to

    compute the percentage change in P and Q relative to

    the averageof the two prices and the averageof the two quantities,

    rather than just the change relative to one point or the other. Loosely

    speaking, this gives an "average" elasticity for the section of the

    actual demand curvei.e., the arcof the curvebetween the two

    points. As a result, this measure is known as thearc elasticity, in this

    case with respect to the price of the good. The arc elasticity is

    defined mathematically as:[13][17][18]

    This method for computing the price elasticity is also known as

    the "midpoints formula", because the average price and average

    quantity are the coordinates of the midpoint of the straight line

    between the two given points.[12][18]

    However, because this

    formula implicitly assumes the section of the demand curve

    between those points is linear, the greater the curvature of the

    actual demand curve is over that range, the worse this

    approximation of its elasticity will be.[17][19]

    [edit]History

    http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Wessels2000-14http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Wessels2000-14http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-15http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-15http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-15http://en.wikipedia.org/wiki/Demand_schedulehttp://en.wikipedia.org/wiki/Demand_schedulehttp://en.wikipedia.org/wiki/Demand_schedulehttp://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=3http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=3http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=3http://en.wikipedia.org/wiki/Arc_elasticityhttp://en.wikipedia.org/wiki/Arc_elasticityhttp://en.wikipedia.org/wiki/Arc_elasticityhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ferguson-12http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ferguson-12http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-McConnell.3B_Brue-17http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-McConnell.3B_Brue-17http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ruffin-11http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ruffin-11http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ruffin-11http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall-16http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall-16http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall-16http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=4http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=4http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=4http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=4http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall-16http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall-16http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ruffin-11http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ruffin-11http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-McConnell.3B_Brue-17http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ferguson-12http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Ferguson-12http://en.wikipedia.org/wiki/Arc_elasticityhttp://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=3http://en.wikipedia.org/wiki/Demand_schedulehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-15
  • 8/3/2019 Velly Economics 1 Q ANS

    5/13

    The illustration that accompanied Marshall's original

    definition of PED, the ratio of PT to Pt

    Together with the concept of an economic "elasticity"

    coefficient,Alfred Marshallis credited with defining PED

    ("elasticity of demand") in his bookPrinciples of Economics,

    published in 1890.[20]

    He described it thus: "And we may say

    generally: the elasticity (or responsiveness) of demand in a

    market is great or small according as the amount demanded

    increases much or little for a given fall in price, and diminishes

    much or little for a given rise in price".[21]

    He reasons this since

    "the only universal law as to a person's desire for a commodity

    is that it diminishes... but this diminution may be slow or rapid. If

    it is slow... a small fall in price will cause a comparatively large

    increase in his purchases. But if it is rapid, a small fall in price

    will cause only a very small increase in his purchases. In the

    former case... the elasticity of his wants, we may say, is great. In

    the latter case... the elasticity of his demand is

    small."[22]

    Mathematically, the Marshallian PED was based on a

    point-price definition, using differential calculus to calculate

    elasticities.[23]

    [edit]DeterminantsThe overriding factor in determining PED is the willingness and

    ability of consumers after a price change to postpone immediate

    consumption decisions concerning the good and to search for

    substitutes ("wait and look").[24]

    A number of factors can thus

    affect the elasticity of demand for a good:[25]

    http://en.wikipedia.org/wiki/Alfred_Marshallhttp://en.wikipedia.org/wiki/Alfred_Marshallhttp://en.wikipedia.org/wiki/Alfred_Marshallhttp://en.wikipedia.org/wiki/Principles_of_Economics_(Marshall)http://en.wikipedia.org/wiki/Principles_of_Economics_(Marshall)http://en.wikipedia.org/wiki/Principles_of_Economics_(Marshall)http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-19http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-19http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-19http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-20http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-20http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-20http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-21http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-21http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-21http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-22http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-22http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-22http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=5http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=5http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=5http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Negbennebor.2C_Microeconomics_2001-23http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Negbennebor.2C_Microeconomics_2001-23http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Negbennebor.2C_Microeconomics_2001-23http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/File:Marshall_PED.pnghttp://en.wikipedia.org/wiki/File:Marshall_PED.pnghttp://en.wikipedia.org/wiki/File:Marshall_PED.pnghttp://en.wikipedia.org/wiki/File:Marshall_PED.pnghttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Negbennebor.2C_Microeconomics_2001-23http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=5http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-22http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-21http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-20http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-19http://en.wikipedia.org/wiki/Principles_of_Economics_(Marshall)http://en.wikipedia.org/wiki/Alfred_Marshall
  • 8/3/2019 Velly Economics 1 Q ANS

    6/13

    Availability ofsubstitute goods: the more and closer the

    substitutes available, the higher the elasticity is likely to be,

    as people can easily switch from one good to another if an

    even minor price change is made;[25][26][27]

    There is a strong

    substitution effect.[28]If no close substitutes are available the

    substitution of effect will be small and the demand

    inelastic.[29]

    Breadth of definition of a good: the broader the

    definition of a good (or service), the lower the elasticity.

    For example, Company X's fish and chips would tend to

    have a relatively high elasticity of demand if a

    significant number of substitutes are available, whereas

    food in general would have an extremely low elasticityof demand because no substitutes exist.

    [30]

    Percentage of income: the higher the percentage of the

    consumer's income that the product's price represents, the

    higher the elasticity tends to be, as people will pay more

    attention when purchasing the good because of its

    cost;[25][26]

    The income effect is substantial.[31]

    When the

    goods represent only a negligible portion of the budget the

    income effect will be insignificant and demand inelastic,[32]

    Necessity: the more necessary a good is, the lower the

    elasticity, as people will attempt to buy it no matter the

    price, such as the case ofinsulinfor those that need it.[10][26]

    Duration: for most goods, the longer a price change holds,

    the higher the elasticity is likely to be, as more and more

    consumers find they have the time and inclination to search

    for substitutes.[25][27]

    When fuel prices increase suddenly, for

    instance, consumers may still fill up their empty tanks in the

    short run, but when prices remain high over several years,

    more consumers will reduce their demand for fuel by

    switching tocarpoolingor public transportation, investing in

    vehicles with greaterfuel economyor taking other

    measures.[26]

    This does not hold forconsumer

    durablessuch as the cars themselves, however; eventually,

    http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Substitute_goodhttp://en.wikipedia.org/wiki/Substitute_goodhttp://en.wikipedia.org/wiki/Substitute_goodhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-GoodwinNelsonAckermanWeisskopf-26http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-GoodwinNelsonAckermanWeisskopf-26http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-27http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-27http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-27http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-28http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-28http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-28http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie48-29http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie48-29http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie48-29http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-30http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-30http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-30http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-31http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-31http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-31http://en.wikipedia.org/wiki/Insulinhttp://en.wikipedia.org/wiki/Insulinhttp://en.wikipedia.org/wiki/Insulinhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Carpoolhttp://en.wikipedia.org/wiki/Carpoolhttp://en.wikipedia.org/wiki/Carpoolhttp://en.wikipedia.org/wiki/Fuel_economy_in_automobileshttp://en.wikipedia.org/wiki/Fuel_economy_in_automobileshttp://en.wikipedia.org/wiki/Fuel_economy_in_automobileshttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-illinois-25http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-illinois-25http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-illinois-25http://en.wikipedia.org/wiki/Consumer_durablehttp://en.wikipedia.org/wiki/Consumer_durablehttp://en.wikipedia.org/wiki/Consumer_durablehttp://en.wikipedia.org/wiki/Consumer_durablehttp://en.wikipedia.org/wiki/Consumer_durablehttp://en.wikipedia.org/wiki/Consumer_durablehttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-illinois-25http://en.wikipedia.org/wiki/Fuel_economy_in_automobileshttp://en.wikipedia.org/wiki/Carpoolhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Insulinhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-31http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-30http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie48-29http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-28http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-27http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-GoodwinNelsonAckermanWeisskopf-26http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin-24http://en.wikipedia.org/wiki/Substitute_good
  • 8/3/2019 Velly Economics 1 Q ANS

    7/13

    it may become necessary for consumers to replace their

    present cars, so one would expect demand to be less

    elastic.[26]

    Brand loyalty: an attachment to a certain brandeither out

    of tradition or because of proprietary barrierscan override

    sensitivity to price changes, resulting in more inelastic

    demand.[30][33]

    Who pays: where the purchaser does not directly pay for

    the good they consume, such as with corporate expense

    accounts, demand is likely to be more inelastic.[33]

    [edit]Interpreting values of priceelasticity coefficients

    Perfectly inelastic demand[10]

    Perfectly elastic demand[10]

    http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-illinois-25http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-illinois-25http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-illinois-25http://en.wikipedia.org/wiki/Brand_loyaltyhttp://en.wikipedia.org/wiki/Brand_loyaltyhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie48-29http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie48-29http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie48-29http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-png62-32http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-png62-32http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-png62-32http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=6http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=6http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=6http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/File:Elasticity-elastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-elastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-inelastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-inelastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-elastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-elastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-inelastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-inelastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-elastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-elastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-inelastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-inelastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-elastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-elastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-inelastic.pnghttp://en.wikipedia.org/wiki/File:Elasticity-inelastic.pnghttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=6http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-png62-32http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie48-29http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Gillespie48-29http://en.wikipedia.org/wiki/Brand_loyaltyhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-illinois-25
  • 8/3/2019 Velly Economics 1 Q ANS

    8/13

    Elasticities of demand are interpreted as follows:[10]

    Value Descriptive Terms

    Ed = 0 Perfectly inelastic demand

    - 1 < Ed < 0 Inelastic or relatively inelastic demand

    Ed = - 1Unit elastic, unit elasticity, unitary elasticity, or unitarily elastic

    demand

    - < Ed < -1

    Elastic or relatively elastic demand

    Ed = - Perfectly elastic demand

    A decrease in the price of a good normally results in an increase

    in the quantity demanded by consumers because of thelaw of

    demand, and conversely, quantity demanded decreases when

    price rises. As summarized in the table above, the PED for a

    good or service is referred to by different descriptive terms

    depending on whether the elasticity coefficient is greater than,

    equal to, or less than 1. That is, the demand for a good is

    called:

    relatively inelasticwhen the percentage change in quantity

    demanded is less thanthe percentage change in price (so

    that Ed > - 1);

    unit elastic, unit elasticity, unitary elasticity, or unitarily

    elasticdemand when the percentage change in quantity

    demanded is equal tothe percentage change in price (so

    that Ed = - 1); and

    http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Law_of_demandhttp://en.wikipedia.org/wiki/Law_of_demandhttp://en.wikipedia.org/wiki/Law_of_demandhttp://en.wikipedia.org/wiki/Law_of_demandhttp://en.wikipedia.org/wiki/Law_of_demandhttp://en.wikipedia.org/wiki/Law_of_demandhttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9
  • 8/3/2019 Velly Economics 1 Q ANS

    9/13

    relatively elasticwhen the percentage change in quantity

    demanded is greater thanthe percentage change in price

    (so that Ed < - 1).[10]

    As the two accompanying diagrams show, perfectly

    elasticdemand is represented graphically as a horizontal line,

    and perfectly inelasticdemand as a vertical line. These are

    the onlycases in which the PED and the slope of the demand

    curve (P/Q) are bothconstant, as well as the onlycases in

    which the PED is determined solely by the slope of the demand

    curve (or more precisely, by the inverseof that slope).[10]

    [edit]Effect on total revenue

    See also:Total revenue test

    A set of graphs shows the relationship between

    demand and total revenue (TR) for a linear demandcurve. As price decreases in the elastic range, TR

    increases, but in the inelastic range, TR decreases.

    TR is maximised at the quantity where PED = 1.

    http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=7http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=7http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=7http://en.wikipedia.org/wiki/Total_revenue_testhttp://en.wikipedia.org/wiki/Total_revenue_testhttp://en.wikipedia.org/wiki/Total_revenue_testhttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand_and_revenue.svghttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand_and_revenue.svghttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand_and_revenue.svghttp://en.wikipedia.org/wiki/File:Price_elasticity_of_demand_and_revenue.svghttp://en.wikipedia.org/wiki/Total_revenue_testhttp://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=7http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-parkin75-9
  • 8/3/2019 Velly Economics 1 Q ANS

    10/13

    A firm considering a price change must know what effect the

    change in price will have on total revenue. Generally any

    change in price will have two effects:[34]

    the price effect: an increase in unit price will tend to

    increase revenue, while a decrease in price will tend to

    decrease revenue.

    the quantity effect: an increase in unit price will tend to lead

    to fewer units sold, while a decrease in unit price will tend to

    lead to more units sold.

    Because of the inverse nature of the relationship between price

    and quantity demanded (i.e., the law of demand), the two effects

    affect total revenue in opposite directions. But in determiningwhether to increase or decrease prices, a firm needs to know

    what the net effect will be. Elasticity provides the answer: The

    percentage change in total revenue is equal to the percentage

    change in quantity demanded plus the percentage change in

    price. (One change will be positive, the other negative.)[35]

    As a result, the relationship between PED and total revenue can

    be described for any good:[36][37]

    When the price elasticity of demand for agoodis perfectly

    inelastic(Ed = 0), changes in the price do not affect the

    quantity demanded for the good; raising prices will cause

    total revenue to increase.

    When the price elasticity of demand for a good is relatively

    inelastic(-1 < Ed < 0), the percentage change in quantity

    demanded is smaller than that in price. Hence, when the

    price is raised, the total revenue rises, and vice versa.

    When the price elasticity of demand for a good is unit (or

    unitary) elastic(Ed = -1), the percentage change in quantity

    is equal to that in price, so a change in price will not affect

    total revenue.

    When the price elasticity of demand for a good is relatively

    elastic( - < Ed < -1), the percentage change in quantity

    http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-33http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-33http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-33http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-34http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-34http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-34http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-35http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-35http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-35http://en.wikipedia.org/wiki/Good_(economics_and_accounting)http://en.wikipedia.org/wiki/Good_(economics_and_accounting)http://en.wikipedia.org/wiki/Good_(economics_and_accounting)http://en.wikipedia.org/wiki/Good_(economics_and_accounting)http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-35http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-35http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-34http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-33
  • 8/3/2019 Velly Economics 1 Q ANS

    11/13

    demanded is greater than that in price. Hence, when the

    price is raised, the total revenue falls, and vice versa.

    When the price elasticity of demand for a good is perfectly

    elastic(Edis ), any increase in the price, no matter how

    small, will cause demand for the good to drop to zero.

    Hence, when the price is raised, the total revenue falls to

    zero.

    Hence, as the accompanying diagram shows, total revenue is

    maximized at the combination of price and quantity demanded

    where the elasticity of demand is unitary.[37]

    It is important to realize that price-elasticity of demand

    is notnecessarily constant over all price ranges. The linear

    demand curve in the accompanying diagram illustrates that

    changes in price also change the elasticity: the price elasticity is

    different at every point on the curve.

    [edit]Effect on tax incidence

    When demand is more elastic than supply, producers

    will bear a greater proportion of the tax burden than

    consumers will.

    Main article:tax incidence

    PEDs, in combination withprice elasticity of supply(PES), can

    be used to assess where the incidence (or "burden") of a per-

    unit tax is falling or to predict where it will fall if the tax is

    imposed. For example, when demand is perfectly inelastic, by

    definition consumers have no alternative to purchasing the good

    or service if the price increases, so the quantity demanded

    http://en.wikipedia.org/wiki/Infinity_(mathematics)http://en.wikipedia.org/wiki/Infinity_(mathematics)http://en.wikipedia.org/wiki/Infinity_(mathematics)http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Arnold2008-36http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Arnold2008-36http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Arnold2008-36http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=8http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=8http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=8http://en.wikipedia.org/wiki/Tax_incidencehttp://en.wikipedia.org/wiki/Tax_incidencehttp://en.wikipedia.org/wiki/Tax_incidencehttp://en.wikipedia.org/wiki/Price_elasticity_of_supplyhttp://en.wikipedia.org/wiki/Price_elasticity_of_supplyhttp://en.wikipedia.org/wiki/Price_elasticity_of_supplyhttp://en.wikipedia.org/wiki/File:Tax_incidence_(mixed).svghttp://en.wikipedia.org/wiki/File:Tax_incidence_(mixed).svghttp://en.wikipedia.org/wiki/File:Tax_incidence_(mixed).svghttp://en.wikipedia.org/wiki/File:Tax_incidence_(mixed).svghttp://en.wikipedia.org/wiki/Price_elasticity_of_supplyhttp://en.wikipedia.org/wiki/Tax_incidencehttp://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=8http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-Arnold2008-36http://en.wikipedia.org/wiki/Infinity_(mathematics)
  • 8/3/2019 Velly Economics 1 Q ANS

    12/13

    would remain constant. Hence, suppliers can increase the price

    by the full amount of the tax, and the consumer would end up

    paying the entirety. In the opposite case, when demand

    isperfectly elastic, by definition consumers have an infinite ability

    to switch to alternatives if the price increases, so they would

    stop buying the good or service in question completely

    quantity demanded would fall to zero. As a result, firms cannot

    pass on any part of the tax by raising prices, so they would be

    forced to pay all of it themselves.[38]

    In practice, demand is likely to be only relativelyelastic or

    relatively inelastic, that is, somewhere between the extreme

    cases of perfect elasticity or inelasticity. More generally, then,

    the higherthe elasticity of demand compared to PES, the

    heavier the burden on producers; conversely, the

    more inelasticthe demand compared to PES, the heavier the

    burden on consumers. The general principle is that the party

    (i.e., consumers or producers) that has feweropportunities to

    avoid the tax by switching to alternatives will bear

    the greaterproportion of the tax burden.[38]

    [edit]Selected price elasticities

    Various research methods are used to calculate price elasticities

    in real life, including analysis of historic sales data, both public

    and private, and use of present-day surveys of customers'

    preferences to build uptest marketscapable of modelling such

    changes. Alternatively,conjoint analysis(a ranking of users'

    preferences which can then be statistically analysed) may be

    used.[39]

    Though PEDs for most demand schedules vary depending on

    price, they can be modeled assuming constant

    elasticity.[40]

    Using this method, the PEDs for various goods

    intended to act as examples of the theory described aboveare

    as follows. For suggestions on why these goods and services

    may have the PED shown, see the above section on

    determinants of price elasticity.

    http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall57-37http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall57-37http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall57-37http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall57-37http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall57-37http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall57-37http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=9http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=9http://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=9http://en.wikipedia.org/wiki/Marketing_researchhttp://en.wikipedia.org/wiki/Marketing_researchhttp://en.wikipedia.org/wiki/Marketing_researchhttp://en.wikipedia.org/wiki/Conjoint_analysishttp://en.wikipedia.org/wiki/Conjoint_analysishttp://en.wikipedia.org/wiki/Conjoint_analysishttp://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-38http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-38http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-38http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-39http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-39http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-39http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-39http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-38http://en.wikipedia.org/wiki/Conjoint_analysishttp://en.wikipedia.org/wiki/Marketing_researchhttp://en.wikipedia.org/w/index.php?title=Price_elasticity_of_demand&action=edit&section=9http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall57-37http://en.wikipedia.org/wiki/Price_elasticity_of_demand#cite_note-wall57-37
  • 8/3/2019 Velly Economics 1 Q ANS

    13/13