平狄克微观经济学课件(英文-(3)

Fernando&YvonnQuijanoPreparedby:ConsumerBehavior3CHAPTERCopyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.Chapter3:ConsumerBehavior2of37Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.CHAPTER3OUTLINE3.1ConsumerPreferences3.2BudgetConstraints3.3ConsumerChoice3.4RevealedPreference3.5MarginalUtilityandConsumerChoice3.6Cost-of-LivingIndexesChapter3:ConsumerBehavior3of37Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.ConsumerBehavior●theoryofconsumerbehaviorDescriptionofhowconsumersallocateincomesamongdifferentgoodsandservicestomaximizetheirwell-being.Consumerbehaviorisbestunderstoodinthreedistinctsteps:1.Consumerpreferences2.Budgetconstraints3.ConsumerchoicesChapter3:ConsumerBehavior4of37Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.CONSUMERPREFERENCES3.1MarketBaskets●marketbasket(orbundle)Listwithspecificquantitiesofoneormoregoods.TABLE3.1AlternativeMarketBasketsA2030B1050D4020E3040G1020H1040MarketBasketUnitsofFoodUnitsofClothingToexplainthetheoryofconsumerbehavior,wewillaskwhetherconsumerspreferonemarketbaskettoanother.Chapter3:ConsumerBehavior5of37Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.CONSUMERPREFERENCES3.1SomeBasicAssumptionsaboutPreferences1.Completeness:Preferencesareassumedtobecomplete.Inotherwords,consumerscancompareandrankallpossiblebaskets.Thus,foranytwomarketbasketsAandB,aconsumerwillpreferAtoB,willpreferBtoA,orwillbeindifferentbetweenthetwo.Byindifferentwemeanthatapersonwillbeequallysatisfiedwitheitherbasket.Notethatthesepreferencesignorecosts.Aconsumermightprefersteaktohamburgerbutbuyhamburgerbecauseitischeaper.Chapter3:ConsumerBehavior6of37Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.CONSUMERPREFERENCES3.1SomeBasicAssumptionsaboutPreferences2.Transitivity:Preferencesaretransitive.TransitivitymeansthatifaconsumerprefersbasketAtobasketBandbasketBtobasketC,thentheconsumeralsoprefersAtoC.Transitivityisnormallyregardedasnecessaryforconsumerconsistency.3.Moreisbetterthanless:Goodsareassumedtobedesirable—i.e.,tobegood.Consequently,consumersalwaysprefermoreofanygoodtoless.Inaddition,consumersareneversatisfiedorsatiated;moreisalwaysbetter,evenifjustalittlebetter.Thisassumptionismadeforpedagogicreasons;namely,itsimplifiesthegraphicalanalysis.Ofcourse,somegoods,suchasairpollution,maybeundesirable,andconsumerswillalwayspreferless.Weignorethese“bads”inthecontextofourimmediatediscussion.Chapter3:ConsumerBehavior7of37Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.DescribingIndividualPreferencesBecausemoreofeachgoodispreferredtoless,wecancomparemarketbasketsintheshadedareas.BasketAisclearlypreferredtobasketG,whileEisclearlypreferredtoA.However,AcannotbecomparedwithB,D,orHwithoutadditionalinformation.CONSUMERPREFERENCES3.1Figure3.1IndifferencecurvesChapter3:ConsumerBehavior8of37Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.TheindifferencecurveU1thatpassesthroughmarketbasketAshowsallbasketsthatgivetheconsumerthesamelevelofsatisfactionasdoesmarketbasketA;theseincludebasketsBandD.AnIndifferenceCurveCONSUMERPREFERENCES3.1Figure3.2Indifferencecurves●indifferencecurveCurverepresentingallcombinationsofmarketbasketsthatprovideaconsumerwiththesamelevelofsatisfaction.OurconsumerprefersbasketE,whichliesaboveU1,toA,butprefersAtoHorG,whichliebelowU1.Chapter3:ConsumerBehavior9of37Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.Anindifferencemapisasetofindifferencecurvesthatdescribesaperson'spreferences.AnIndifferenceMapCONSUMERPREFERENCES3.1Figure3.3IndifferenceMaps●indifferencemapGraphcontainingasetofindifferencecurvesshowingthemarketbasketsamongwhichaconsumerisindifferent.AnymarketbasketonindifferencecurveU3,suchasbasketA,ispreferredtoanybasketoncurveU2(e.g.,basketB),whichinturnispreferredtoanybasketonU1,suchasD.Chapter3:ConsumerBehavior10of37Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.IfindifferencecurvesU1andU2intersect,oneoftheassumptionsofconsumertheoryisviolated.IndifferenceCurvesCannotIntersectCONSUMERPREFERENCES3.1Figure3.4IndifferenceMapsAccordingtothisdiagram,theconsumershouldbeindifferentamongmarketbasketsA,B,andD.YetBshouldbepreferredtoDbecauseBhasmoreofbothgoodsChapter3:ConsumerBehavior11of37Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.Themagnitudeoftheslopeofanindifferencecurvemeasurestheconsumer’smarginalrateofsubstitution(MRS)betweentwogoods.TheMarginalRateofSubstitutionCONSUMERPREFERENCES3.1Figure3.5TheMarginalRateofSubstitutionInthisfigure,theMRSbetweenclothing(C)andfood(F)fallsfrom6(betweenAandB)to4(betweenBandD)to2(betweenDandE)to1(betweenEandG).ConvexityThedeclinein