北大院微觀課件

ChapterProducerBehaviorChapterProducerBehavior2005北京大學經(jīng)濟學院ChapterFour北京大學經(jīng)濟學院ChapterFour北京大學經(jīng)濟學院4.14.2Production4.3Cost北京大學經(jīng)濟學院4.2.1Definition北京大學經(jīng)濟學院4.2.1DefinitionofProduct4.2.2TheShort-RunProduction4.2.3TheLong-RunProduction4.2.4OptimalInputsintheLong4.2.5Elastictiesof4.2ProductionReadingsaboutthisZhang:ChapterNicholson:ReadingsaboutthisZhang:ChapterNicholson:Chapter11,P267-北京大學經(jīng)濟學院ChapterFour北京大學經(jīng)濟學院ChapterFour北京大學經(jīng)濟學院4.14.2Production4.3Cost北京大學北京大學經(jīng)濟學院SymmetryBetweenConsumerandFirmUsesimilartoolsfromconsumertheorytoanalysethefirm.Ingeneral:SubjectSubjectconSymmetryBetweenConsumerandFirmUsesimilartoolsfromconsumertheorytoanalysethefirm.Ingeneral:SubjectSubjectcon大學濟學北京大學經(jīng)濟學院北京大學經(jīng)濟學院ProductionTechnology(生產(chǎn)技術ProductionProcessbyProductionTechnology(生產(chǎn)技術ProductionProcessbywhichinputsareconvertedtoInputsalsocalled“factorsofproduction”(生產(chǎn)要素Input（1）:Labor(L)(skilled,Input（2）:Physicalcapital(K)（有形資本）(equipment,structuresinventories（存貨）land),Mainissue:Whichtechnologyis北京大學經(jīng)濟學院Process（生產(chǎn)過程Labour,Goodsand北京大學經(jīng)濟學院Process（生產(chǎn)過程Labour,Goodsand北京大學經(jīng)濟學院DefinitionofProductionxi-theamountDefinitionofProductionxi-theamountused(level)ofinputInputbundle(投入組合)-vectorinputs(x1,x2,…qoutputlevel（產(chǎn)出水平Productionqf(1,L,xnThetechnology’sproductionfunctionstatesthemaximumamountofoutputpossiblefromaninputbundle.北京大學經(jīng)濟學院Productionfunctions–specificq=f(L,K)isageneralformoftheproductionfunctionwithProductionfunctions–specificq=f(L,K)isageneralformoftheproductionfunctionwithtwoOftenweneedtoworkwithmorespecificfunctionalforms.HerearefourcommononesLinear:Fixedproportions:q=min(aL,Cobb-qf(K,L)Ineachcaseq,L,Karevariablesanda,b,c,ρε(andA)北京大學經(jīng)濟學院ShortRunvsLongRun（短期與ShortRunvsLongRun（短期與長期Theshortrunisdefinedastheperiodoftimewhentheplantsizeisfixed.Intheshortrun,atleastonefactorofproductionisfixed(unchangeable)Thelongrunisdefinedasthetimeperiodnecessarytochangetheplantsize.Inthelongrun,allfactorsofproductioncanbechanged…are“variable”Thedurationofthelongrun(andthusthatoftheshortrun)dependsonthenatureoftheproduction北京大學經(jīng)濟學院北京大學經(jīng)濟學院北京大學經(jīng)濟學院ProductionWhenOnlyOneInputisThereareProductionWhenOnlyOneInputisTherearethreeimportantwaystomeasuretheproductivityofinputsinshort-run:TotalAverageMarginal北京大學經(jīng)濟學院TotalProduct(TP)（總產(chǎn)量TotalProductrepresentstherelationshipbetweenthenumberofworkers(orCapitals)andtheTOTALnumberofunitsofoutputproducedholdingallTotalProduct(TP)（總產(chǎn)量TotalProductrepresentstherelationshipbetweenthenumberofworkers(orCapitals)andtheTOTALnumberofunitsofoutputproducedholdingallotherfactorsofproduction(theplantsize)constant.TLTKf(L,Kf(L,K北京大學經(jīng)濟學院TheProductionFunction:TPincreaseswith81234Unitsof北京大學經(jīng)濟學院UnitsTheProductionFunction:TPincreaseswith81234Unitsof北京大學經(jīng)濟學院UnitsTotalProduct,QfVariable1,000dQ0d2Qd2Q0TotalProduct,QfVariable1,000dQ0d2Qd2Q00s北京大學經(jīng)濟InflectionPoint(拐點AverageProduct(AP)(平均產(chǎn)量 Thisfunctionrepresentstheaverageamountof OutputperunitofAverageProduct(AP)(平均產(chǎn)量 Thisfunctionrepresentstheaverageamountof Outputperunitofqf(K,APLLLqf(K, KKK北京大學經(jīng)濟學院AP:slopeofrayfrom)=150e=AP:slopeofrayfrom)=150e=150/10=北京大學經(jīng)濟學院LAP:SlopeofrayfromAP(slopeofray)DecreasesafterL0AP(slopeofray)IncreasesuptoAP:SlopeofrayfromAP(slopeofray)DecreasesafterL0AP(slopeofray)IncreasesuptoL0北京大學經(jīng)濟學院AP:Increases,reachesamaximumandAP(slopeofray)IncreasesuptoLAP:Increases,reachesamaximumandAP(slopeofray)IncreasesuptoL0AP(slopeofray)DecreasesafterL0L北京大學經(jīng)濟學院MarginalProduct(MP)(邊際產(chǎn)量 Theadditionaloutputthatcanbeproducedbyaddingonemoreunitoflabor(orCapital),holdingeverythingelseconstant.TheslopeMarginalProduct(MP)(邊際產(chǎn)量 Theadditionaloutputthatcanbeproducedbyaddingonemoreunitoflabor(orCapital),holdingeverythingelseconstant.TheslopeoftheTotalProductMPfLLMPfKK北京大學經(jīng)濟學院MP:SlopeoftheProductionSlope=30/3=160130MP:SlopeoftheProductionSlope=30/3=1601309北京大學經(jīng)濟學院MP=TheRelationshipbetweenTPandLL北京大學經(jīng)濟學院TheRelationshipbetweenTPandLL北京大學經(jīng)濟學院TheLawofDiminishingReturnTheLawofDiminishingReturnWhathappenstooutputaswehiremoreandmoreworkers?RememberthattheplantsizeisThatmeansthatyouwillbehiringmoreworkerstoSHAREtheEXISTINGEQUIPMENTandtheEXISTINGSPACE.北京大學經(jīng)濟學院TheLawofDiminishingReturnTheLawofDiminishingReturnAsmoreofavariableinput(labor)isaddedtoafixedinput(plant),additionstooutputgetsmallerandNotethataddingworkersincreasesoutputbuttheincreasesbecomesmallerandsmallerasmoreworkersarehired.北京大學經(jīng)濟學院DiminishingMarginalDiminishingMPKfDiminishingMarginalDiminishingMPKfMPLf北京大學經(jīng)濟學院MarginalProducts:DiminishingMPqx1/3x2/12MPMP(2/MarginalProducts:DiminishingMPqx1/3x2/12MPMP(2/11M122122x5/3x2/129291/14/2xx2Bothmarginalproductsare北京大學經(jīng)濟學院TheReasonsofDiminishingIncreasingReturnsSpecialization（專業(yè)化TheReasonsofDiminishingIncreasingReturnsSpecialization（專業(yè)化DiminishingReturnsBeginsFeweropportunitiesforteamworkandspecializationL北京大學經(jīng)濟學院TheRelationshipbetweenAPandLL北京大學經(jīng)濟學院TheRelationshipbetweenAPandLL北京大學經(jīng)濟學院RelationshipbetweenMPandMPMP=APwhenAPisRelationshipbetweenMPandMPMP=APwhenAPisMPaboveMPbelow北京大學經(jīng)濟TheRelationshipbetweenAPand IfMPTheRelationshipbetweenAPand IfMP>AP,thentheAverageProductIfMP<thentheAPwillIfMP=AP,thentheAPisnotincreasingordecreasing:itisatthemaximumpoint.北京大學經(jīng)濟學院ProofofRelationshipsbetweenAPand,wecanqf(K,APProofofRelationshipsbetweenAPand,wecanqf(K,AP LLLdAPLLMPLSo,atamaximumL,L·MPL=qor北京大學經(jīng)濟學院ThreeStagesof（生產(chǎn)的三個階段北京ThreeStagesof（生產(chǎn)的三個階段北京大學經(jīng)濟學院ThreeStagesofProduction（生產(chǎn)的三個階段qTotalProduct,qfVariable00qLqLAverageVariable001