平狄克微观经济学课件(英文)12

Fernando&YvonnQuijanoPreparedby:MonopolisticCompetitionandOligopoly12CHAPTERCopyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.Chapter12:MonopolisticCompetitionandOligopoly2of35Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.CHAPTER12OUTLINE12.1MonopolisticCompetition12.2Oligopoly12.3PriceCompetition12.4CompetitionversusCollusion:ThePrisoners’Dilemma12.5ImplicationsofthePrisoners’DilemmaforOligopolisticPricing12.6CartelsChapter12:MonopolisticCompetitionandOligopoly3of35Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.MonopolisticCompetitionandOligopoly●monopolisticcompetitionMarketinwhichfirmscanenterfreely,eachproducingitsownbrandorversionofadifferentiatedproduct.●oligopolyMarketinwhichonlyafewfirmscompetewithoneanother,andentrybynewfirmsisimpeded.●cartelMarketinwhichsomeorallfirmsexplicitlycollude,coordinatingpricesandoutputlevelstomaximizejointprofits.Chapter12:MonopolisticCompetitionandOligopoly4of35Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.MONOPOLISTICCOMPETITION12.1TheMakingsofMonopolisticCompetitionAmonopolisticallycompetitivemarkethastwokeycharacteristics:1.Firmscompetebysellingdifferentiatedproductsthatarehighlysubstitutableforoneanotherbutnotperfectsubstitutes.Inotherwords,thecross-priceelasticitiesofdemandarelargebutnotinfinite.2.Thereisfreeentryandexit:itisrelativelyeasyfornewfirmstoenterthemarketwiththeirownbrandsandforexistingfirmstoleaveiftheirproductsbecomeunprofitable.Chapter12:MonopolisticCompetitionandOligopoly5of35Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.MONOPOLISTICCOMPETITION12.1EquilibriumintheShortRunandtheLongRunBecausethefirmistheonlyproducerofitsbrand,itfacesadownward-slopingdemandcurve.Priceexceedsmarginalcostandthefirmhasmonopolypower.Intheshortrun,describedinpart(a),pricealsoexceedsaveragecost,andthefirmearnsprofitsshownbytheyellow-shadedrectangle.AMonopolisticallyCompetitiveFirmintheShortandLongRunFigure12.1Chapter12:MonopolisticCompetitionandOligopoly6of35Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.MONOPOLISTICCOMPETITION12.1EquilibriumintheShortRunandtheLongRunInthelongrun,theseprofitsattractnewfirmswithcompetingbrands.Thefirm’smarketsharefalls,anditsdemandcurveshiftsdownward.Inlong-runequilibrium,describedinpart(b),priceequalsaveragecost,sothefirmearnszeroprofiteventhoughithasmonopolypower.AMonopolisticallyCompetitiveFirmintheShortandLongRunFigure12.1(continued)Chapter12:MonopolisticCompetitionandOligopoly7of35Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.MONOPOLISTICCOMPETITION12.1MonopolisticCompetitionandEconomicEfficiencyUnderperfectcompetition,priceequalsmarginalcost.Thedemandcurvefacingthefirmishorizontal,sothezero-profitpointoccursatthepointofminimumaveragecost.ComparisonofMonopolisticallyCompetitiveEquilibriumandPerfectlyCompetitiveEquilibriumFigure12.2Chapter12:MonopolisticCompetitionandOligopoly8of35Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.MONOPOLISTICCOMPETITION12.1MonopolisticCompetitionandEconomicEfficiencyUndermonopolisticcompetition,priceexceedsmarginalcost.Thusthereisadeadweightloss,asshownbytheyellow-shadedarea.Thedemandcurveisdownward-sloping,sothezero-profitpointistotheleftofthepointofminimumaveragecost.ComparisonofMonopolisticallyCompetitiveEquilibriumandPerfectlyCompetitiveEquilibriumFigure12.2(continued)Inbothtypesofmarkets,entryoccursuntilprofitsaredriventozero.Inevaluatingmonopolisticcompetition,theseinefficienciesmustbebalancedagainstthegainstoconsumersfromproductdiversity.Chapter12:MonopolisticCompetitionandOligopoly9of35Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.MONOPOLISTICCOMPETITION12.1TABLE12.1ElasticitiesofDemandforBrandsofColasandCoffeeBrandElasticityofDemandColasRoyalCrown–2.4Coke–5.2to–5.7GroundcoffeeFolgers–6.4MaxwellHouse–8.2ChockFullo’Nuts–3.6WiththeexceptionofRoyalCrownandChockFullo’Nuts,allthecolasandcoffeesarequitepriceelastic.Withelasticitiesontheorderof−4to−8,eachbrandhasonlylimitedmonopolypower.Thisistypicalofmonopolisticcompetition.Chapter12:MonopolisticCompetitionandOligopoly10of35Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.OLIGOPOLY12.2TheMakingsofMonopolisticCompetitionInoligopolisticmarkets,theproductsmayormaynotbedifferentiated.Whatmattersisthatonlyafewfirmsaccountformostoralloftotalproduction.Insomeoligopolisticmarkets,someorallfirmsearnsubstantialprofitsoverthelongrunbecausebarrierstoentrymakeitdifficultorimpossiblefornewfirmstoenter.Oligopolyisaprevalentformofmarketstructure.Examplesofoligopolisticindustriesincludeautomobiles,steel,aluminum,petrochemicals,electricalequipment,andcomputers.Chapter12:MonopolisticCompetition