平狄克微观经济学课件(英文)09

Fernando&YvonnQuijanoPreparedby:TheAnalysisofCompetitiveMarkets9CHAPTERCopyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.Chapter9:TheAnalysisofCompetitiveMarkets2of28Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.CHAPTER9OUTLINE9.1EvaluatingtheGainsandLossesfromGovernmentPolicies—ConsumerandProducerSurplus9.2TheEfficiencyofaCompetitiveMarket9.3MinimumPrices9.4PriceSupportsandProductionQuotas9.5ImportQuotasandTariffs9.6TheImpactofaTaxorSubsidyChapter9:TheAnalysisofCompetitiveMarkets3of28Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.EVALUATINGTHEGAINSANDLOSSESFROMGOVERNMENTPOLICIES—CONSUMERANDPRODUCERSURPLUS9.1ReviewofConsumerandProducerSurplusConsumerAwouldpay$10foragoodwhosemarketpriceis$5andthereforeenjoysabenefitof$5.ConsumerBenjoysabenefitof$2,andConsumerC,whovaluesthegoodatexactlythemarketprice,enjoysnobenefit.Consumersurplus,whichmeasuresthetotalbenefittoallconsumers,istheyellow-shadedareabetweenthedemandcurveandthemarketprice.ConsumerandProducerSurplusFigure9.1Chapter9:TheAnalysisofCompetitiveMarkets4of28Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.EVALUATINGTHEGAINSANDLOSSESFROMGOVERNMENTPOLICIES—CONSUMERANDPRODUCERSURPLUS9.1ReviewofConsumerandProducerSurplusProducersurplusmeasuresthetotalprofitsofproducers,plusrentstofactorinputs.Itisthebenefitthatlower-costproducersenjoybysellingatthemarketprice,shownbythegreen-shadedareabetweenthesupplycurveandthemarketprice.Together,consumerandproducersurplusmeasurethewelfarebenefitofacompetitivemarket.ConsumerandProducerSurplus(continued)Figure9.1Chapter9:TheAnalysisofCompetitiveMarkets5of28Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.EVALUATINGTHEGAINSANDLOSSESFROMGOVERNMENTPOLICIES—CONSUMERANDPRODUCERSURPLUS9.1ApplicationofConsumerandProducerSurplus●welfareeffectsGainsandlossestoconsumersandproducers.ThepriceofagoodhasbeenregulatedtobenohigherthanPmax,whichisbelowthemarket-clearingpriceP0.ThegaintoconsumersisthedifferencebetweenrectangleAandtriangleB.ThelosstoproducersisthesumofrectangleAandtriangleC.TrianglesBandCtogethermeasurethedeadweightlossfrompricecontrols.ChangeinConsumerandProducerSurplusfromPriceControlsFigure9.2●deadweightlossNetlossoftotal(consumerplusproducer)surplus.Chapter9:TheAnalysisofCompetitiveMarkets6of28Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.EVALUATINGTHEGAINSANDLOSSESFROMGOVERNMENTPOLICIES—CONSUMERANDPRODUCERSURPLUS9.1ApplicationofConsumerandProducerSurplusIfdemandissufficientlyinelastic,triangleBcanbelargerthanrectangleA.Inthiscase,consumerssufferanetlossfrompricecontrols.EffectofPriceControlsWhenDemandIsInelasticFigure9.3Chapter9:TheAnalysisofCompetitiveMarkets7of28Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.EVALUATINGTHEGAINSANDLOSSESFROMGOVERNMENTPOLICIES—CONSUMERANDPRODUCERSURPLUS9.1Supply:QS=15.90+0.72PG+0.05PODemand:QD=−10.35−0.18PG+0.69POThemarket-clearingpriceofnaturalgasis$6.40permcf,andthe(hypothetical)maximumallowablepriceis$3.00.Ashortageof23.6−20.6=3.0Tcfresults.ThegaintoconsumersisrectangleAminustriangleB,andthelosstoproducersisrectangleAplustriangleC.ThedeadweightlossisthesumoftrianglesBplusC.EffectsofNaturalGasPriceControlsFigure9.4Chapter9:TheAnalysisofCompetitiveMarkets8of28Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.THEEFFICIENCYOFACOMPETITIVEMARKET9.2MarketFailureTherearetwoimportantinstancesinwhichmarketfailurecanoccur:1.Externalities2.LackofInformation●economicefficiencyMaximizationofaggregateconsumerandproducersurplus.●marketfailureSituationinwhichanunregulatedcompetitivemarketisinefficientbecausepricesfailtoprovidepropersignalstoconsumersandproducers.●externalityActiontakenbyeitheraproduceroraconsumerwhichaffectsotherproducersorconsumersbutisnotaccountedforbythemarketprice.Chapter9:TheAnalysisofCompetitiveMarkets9of28Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.THEEFFICIENCYOFACOMPETITIVEMARKET9.2WhenpriceisregulatedtobenolowerthanP2,onlyQ3willbedemanded.IfQ3isproduced,thedeadweightlossisgivenbytrianglesBandC.AtpriceP2,producerswouldliketoproducemorethanQ3.Iftheydo,thedeadweightlosswillbeevenlarger.WelfareLossWhenPriceisHeldAboveMarket-ClearingLevelFigure9.5Chapter9:TheAnalysisofCompetitiveMarkets10of28Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.THEEFFICIENCYOFACOMPETITIVEMARKET9.2Supply:QS=16,000+0.4PDemand:QD=32,0000.4PThemarket-clearingpriceis$20,000;atthisprice,about24,000kidneysperyearwouldbesupplied.Thelaweffectivelymakesthepricezero.About16,000kidneysperyeararestilldonated;thisconstrainedsupplyisshownasS’.ThelosstosuppliersisgivenbyrectangleAandtriangleC.Ifconsumersreceivedkidneysatnocost,theirgainwouldbe