平狄克微观经济学课件(英文)04

Fernando&YvonnQuijanoPreparedby:©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.IndividualandMarketDemand4CHAPTERChapter4IndividualandMarketDemand2of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.CHAPTER4OUTLINE4.1IndividualDemand4.2IncomeandSubstitutionEffects4.3MarketDemand4.4ConsumerSurplus4.5NetworkExternalities4.6EmpiricalEstimationofDemandChapter4IndividualandMarketDemand3of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.INDIVIDUALDEMAND4.1PriceChangesEffectofPriceChangesAreductioninthepriceoffood,withincomeandthepriceofclothingfixed,causesthisconsumertochooseadifferentmarketbasket.In(a),thebasketsthatmaximizeutilityforvariouspricesoffood(pointA,$2;B,$1;D,$0.50)traceouttheprice-consumptioncurve.Part(b)givesthedemandcurve,whichrelatesthepriceoffoodtothequantitydemanded.(PointsE,G,andHcorrespondtopointsA,B,andD,respectively).Figure4.1Chapter4IndividualandMarketDemand4of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.INDIVIDUALDEMAND4.1TheIndividualDemandCurve●price-consumptioncurveCurvetracingtheutility-maximizingcombinationsoftwogoodsasthepriceofonechanges.●individualdemandcurveCurverelatingthequantityofagoodthatasingleconsumerwillbuytoitsprice.Chapter4IndividualandMarketDemand5of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.INDIVIDUALDEMAND4.1IncomeChangesEffectofIncomeChangesAnincreaseinincome,withthepricesofallgoodsfixed,causesconsumerstoaltertheirchoiceofmarketbaskets.Inpart(a),thebasketsthatmaximizeconsumersatisfactionforvariousincomes(pointA,$10;B,$20;D,$30)traceouttheincome-consumptioncurve.Theshifttotherightofthedemandcurveinresponsetotheincreasesinincomeisshowninpart(b).(PointsE,G,andHcorrespondtopointsA,B,andD,respectively.)Figure4.2Chapter4IndividualandMarketDemand6of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.INDIVIDUALDEMAND4.1NormalversusInferiorGoodsAnInferiorGoodAnincreaseinaperson’sincomecanleadtolessconsumptionofoneofthetwogoodsbeingpurchased.Here,hamburger,thoughanormalgoodbetweenAandB,becomesaninferiorgoodwhentheincome-consumptioncurvebendsbackwardbetweenBandC.Figure4.3Chapter4IndividualandMarketDemand7of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.INDIVIDUALDEMAND4.1EngelCurvesEngelCurvesEngelcurvesrelatethequantityofagoodconsumedtoincome.In(a),foodisanormalgoodandtheEngelcurveisupwardsloping.In(b),however,hamburgerisanormalgoodforincomelessthan$20permonthandaninferiorgoodforincomegreaterthan$20permonth.Figure4.4●EngelcurveCurverelatingthequantityofagoodconsumedtoincome.Chapter4IndividualandMarketDemand8of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.INDIVIDUALDEMAND4.1Ifthemarketpricewereheldconstant,wewouldexpecttoseeanincreaseinthequantitydemandedasaresultofconsumers’higherincomes.Becausethisincreasewouldoccurnomatterwhatthemarketprice,theresultwouldbeashifttotherightoftheentiredemandcurve.Chapter4IndividualandMarketDemand9of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.INDIVIDUALDEMAND4.1TABLE4.1AnnualU.S.HouseholdConsumerExpendituresINCOMEGROUP(2005$)ExpendituresLessthan10,000-20,000-30,000-40,000-50,00070,000($)on:$10,00019,99929,99939,99949,99969,999andaboveEntertainment84494711911677193324024542OwnedDwelling42724716570167767771897214763RentedDwelling2672277929802977281822551379HeathCare1108187422412361277827463812Food2901324239424552523465709247Clothing86188411061472145019613245Source:U.S.DepartmentofLabor,BureauofLaborStatistics,“ConsumerExpenditureSurvey,AnnualReport2005.”Chapter4IndividualandMarketDemand10of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.INDIVIDUALDEMAND4.1EngelCurvesforU.S.ConsumersAverageper-householdexpendituresonrenteddwellings,healthcare,andentertainmentareplottedasfunctionsofannualincome.Healthcareandentertainmentarenormalgoods,asexpendituresincreasewithincome.Rentalhousing,however,isaninferiorgoodforincomesabove$35,000.Figure4.5Chapter4IndividualandMarketDemand11of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.INDIVIDUALDEMAND4.1SubstitutesandComplementsRecallthat:Twogoodsaresubstitutesifanincreaseinthepriceofoneleadstoanincreaseinthequantitydemandedoftheother.Twogoodsarecomplementsifanincreaseinthepriceofonegoodleadstoadecreaseinthequantitydemandedoftheother.Twogoodsareindependentifachangeinthepriceofonegoodhasnoeffectonthequantitydemandedoftheother.Chapter4IndividualandMarketDemand12of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.INCOMEANDSUBSTITUTIONEFFECTS4.2Afallinthepriceofagoodhastwoeffects:1.Consumerswilltendtobuymoreofthegoodthathasbecomecheaperandlessofthosegoodsthatarenowrelativelymoreexpensive.2.Becauseoneofthegoodsisnowcheaper,consumersenjoyanincreaseinrealpurchasingpower.Chapter4IndividualandMarketDemand13of38©2008PrenticeHallBusinessPublishing•Microeconomics•Pindyck/Rubinfeld,7e.INCOMEANDSUBSTITUTIONEFFECTS4.2In