平狄克微观经济学课件(英文)14

Fernando&YvonnQuijanoPreparedby:MarketsforFactorInputs14CHAPTERCopyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.Chapter14:MarketsforFactorInputs2of31Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.CHAPTER14OUTLINE14.1CompetitiveFactorMarkets14.2EquilibriuminaCompetitiveFactorMarket14.3FactorMarketswithMonopsonyPower14.4FactorMarketswithMonopolyPowerChapter14:MarketsforFactorInputs3of31Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.MARKETSFORFACTORINPUTS14Wewillexaminethreedifferentfactormarketstructures:1.Perfectlycompetitivefactormarkets;2.Marketsinwhichbuyersoffactorshavemonopsonypower;3.Marketsinwhichsellersoffactorshavemonopolypower.Chapter14:MarketsforFactorInputs4of31Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.COMPETITIVEFACTORMARKETS14.1DemandforaFactorInputWhenOnlyOneInputIsVariable●marginalrevenueproductAdditionalrevenueresultingfromthesaleofoutputcreatedbytheuseofoneadditionalunitofaninput.HowdowemeasuretheMRPL?It’stheadditionaloutputobtainedfromtheadditionalunitofthislabor,multipliedbytheadditionalrevenuefromanextraunitofoutput.●deriveddemandDemandforaninputthatdependson,andisderivedfrom,boththefirm’slevelofoutputandthecostofinputs.(14.1)Thisimportantresultholdsforanycompetitivefactormarket,whetherornottheoutputmarketiscompetitive.Chapter14:MarketsforFactorInputs5of31Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.COMPETITIVEFACTORMARKETS14.1DemandforaFactorInputWhenOnlyOneInputIsVariableInacompetitiveoutputmarket,afirmwillsellallitsoutputatthemarketpriceP.Inthiscase,themarginalrevenueproductoflaborisequaltothemarginalproductoflabortimesthepriceoftheproduct:MarginalRevenueProductFigure14.1Inacompetitivefactormarketinwhichtheproducerisapricetaker,thebuyer’sdemandforaninputisgivenbythemarginalrevenueproductcurve.TheMRPcurvefallsbecausethemarginalproductoflaborfallsashoursofworkincrease.Whentheproduceroftheproducthasmonopolypower,thedemandfortheinputisalsogivenbytheMRPcurve.Inthiscase,however,theMRPcurvefallsbecauseboththemarginalproductoflaborandmarginalrevenuefall.(14.2)Chapter14:MarketsforFactorInputs6of31Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.COMPETITIVEFACTORMARKETS14.1DemandforaFactorInputWhenOnlyOneInputIsVariableHiringbyaFirmintheLaborMarket(withFixedCapital)Figure14.2Inacompetitivelabormarket,afirmfacesaperfectlyelasticsupplyoflaborSLandcanhireasmanyworkersasitwantsatawageratew*.Thefirm’sdemandforlaborDLisgivenbyitsmarginalrevenueproductoflaborMRPL.Theprofit-maximizingfirmwillhireL*unitsoflaboratthepointwherethemarginalrevenueproductoflaborisequaltothewagerate.(14.3)Chapter14:MarketsforFactorInputs7of31Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.COMPETITIVEFACTORMARKETS14.1DemandforaFactorInputWhenOnlyOneInputIsVariableAShiftintheSupplyofLaborFigure14.3WhenthesupplyoflaborfacingthefirmsisS1,thefirmhiresL1unitsoflaboratwagew1.ButwhenthemarketwageratedecreasesandthesupplyoflaborshiftstoS2,thefirmmaximizesitsprofitbymovingalongthedemandforlaborcurveuntilthenewwageratew2isequaltothemarginalrevenueproductoflabor.Asaresult,L2unitsoflaborarehired.(14.4)RecallthatMRPL=(MPL)(MR)anddividebothsidesofMRPL=wbythemarginalproductoflabor.Then,Chapter14:MarketsforFactorInputs8of31Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.COMPETITIVEFACTORMARKETS14.1DemandforaFactorInputWhenOnlyOneInputIsVariable(14.4)RecallthatMRPL=(MPL)(MR)anddividebothsidesofequationbythemarginalproductoflabor.Then,Equation(14.4)showsthatboththehiringandoutputchoicesofthefirmfollowthesamerule:Inputsoroutputsarechosensothatmarginalrevenue(fromthesaleofoutput)isequaltomarginalcost(fromthepurchaseofinputs).Thisprincipleholdsinbothcompetitiveandnoncompetitivemarkets.Chapter14:MarketsforFactorInputs9of31Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.COMPETITIVEFACTORMARKETS14.1DemandforaFactorInputWhenSeveralInputsAreVariableFirm’sDemandCurveforLabor(withVariableCapital)Figure14.4Whentwoormoreinputsarevariable,afirm’sdemandforoneinputdependsonthemarginalrevenueproductofbothinputs.Whenthewagerateis$20,Arepresentsonepointonthefirm’sdemandforlaborcurve.Whenthewageratefallsto$15,themarginalproductofcapitalrises,encouragingthefirmtorentmoremachineryandhiremorelabor.Asaresult,theMRPcurveshiftsfromMRPL1toMRPL2,generatinganewpointConthefirm’sdemandforlaborcurve.ThusAandCareonthedemandforlaborcurve,butBisnot.Chapter14:MarketsforFactorInputs10of31Copyright©2009PearsonEducation,Inc.PublishingasPrenticeHall•Microeconomics•Pindyck/Rubinfeld,7e.COMPETITIVEFACTORMARKETS14.1TheMarketDemandCurveTheIndustryDemandforLaborFigure14.5Thedemandcurveforlaborofacompetitivefirm,MRPL1in(a),takestheproductpriceasgiven.Butas