mankiw6e-chap_精品文档优质PPT.ppt
《mankiw6e-chap_精品文档优质PPT.ppt》由会员分享,可在线阅读,更多相关《mankiw6e-chap_精品文档优质PPT.ppt(69页珍藏版)》请在冰豆网上搜索。
thephysicalandmentaleffortsofworkersCHAPTER3NationalIncomeslide4TheproductionfunctiondenotedY=F(K,L)showshowmuchoutput(Y)theeconomycanproducefromKunitsofcapitalandLunitsoflaborreflectstheeconomysleveloftechnologyexhibitsconstantreturnstoscaleCHAPTER3NationalIncomeslide5Returnstoscale:
AreviewInitiallyY1=F(K1,L1)Scaleallinputsbythesamefactorz:
K2=zK1andL2=zL1(e.g.,ifz=1.25,thenallinputsareincreasedby25%)Whathappenstooutput,Y2=F(K2,L2)?
Ifconstantreturnstoscale,Y2=zY1Ifincreasingreturnstoscale,Y2zY1Ifdecreasingreturnstoscale,Y20CHAPTER3NationalIncomeslide7Example2decreasingreturnstoscaleforanyz1CHAPTER3NationalIncomeslide8Example3increasingreturnstoscaleforanyz1CHAPTER3NationalIncomeslide9NowyoutryDeterminewhetherconstant,decreasing,orincreasingreturnstoscaleforeachoftheseproductionfunctions:
(a)(b)CHAPTER3NationalIncomeslide10Answertopart(a)constantreturnstoscaleforanyz0CHAPTER3NationalIncomeslide11Answertopart(b)constantreturnstoscaleforanyz0CHAPTER3NationalIncomeslide12Assumptionsofthemodel1.Technologyisfixed.2.TheeconomyssuppliesofcapitalandlaborarefixedatCHAPTER3NationalIncomeslide13DeterminingGDPOutputisdeterminedbythefixedfactorsuppliesandthefixedstateoftechnology:
CHAPTER3NationalIncomeslide14Thedistributionofnationalincomedeterminedbyfactorprices,thepricesperunitthatfirmspayforthefactorsofproductionwage=priceofLrentalrate=priceofKCHAPTER3NationalIncomeslide15NotationW=nominalwageR=nominalrentalrateP=priceofoutputW/P=realwage(measuredinunitsofoutput)R/P=realrentalrateCHAPTER3NationalIncomeslide16HowfactorpricesaredeterminedFactorpricesaredeterminedbysupplyanddemandinfactormarkets.Recall:
Supplyofeachfactorisfixed.Whataboutdemand?
CHAPTER3NationalIncomeslide17DemandforlaborAssumemarketsarecompetitive:
eachfirmtakesW,R,andPasgiven.Basicidea:
Afirmhireseachunitoflaborifthecostdoesnotexceedthebenefit.cost=realwagebenefit=marginalproductoflaborCHAPTER3NationalIncomeslide18Marginalproductoflabor(MPL)definition:
Theextraoutputthefirmcanproduceusinganadditionalunitoflabor(holdingotherinputsfixed):
MPL=F(K,L+1)F(K,L)CHAPTER3NationalIncomeslide19Exercise:
Compute&
graphMPLa.DetermineMPLateachvalueofL.b.Graphtheproductionfunction.c.GraphtheMPLcurvewithMPLontheverticalaxisandLonthehorizontalaxis.LYMPL00n.a.110?
219?
3278434?
540?
645?
749?
852?
954?
1055?
CHAPTER3NationalIncomeslide20Answers:
CHAPTER3NationalIncomeslide21YoutputMPLandtheproductionfunctionLlabor1MPL1MPL1MPLAsmorelaborisadded,MPLSlopeoftheproductionfunctionequalsMPLCHAPTER3NationalIncomeslide22DiminishingmarginalreturnsAsafactorinputisincreased,itsmarginalproductfalls(otherthingsequal).Intuition:
SupposeLwhileholdingKfixedfewermachinesperworkerlowerworkerproductivityCHAPTER3NationalIncomeslide23Checkyourunderstanding:
Whichoftheseproductionfunctionshavediminishingmarginalreturnstolabor?
CHAPTER3NationalIncomeslide24Exercise(part2)SupposeW/P=6.d.IfL=3,shouldfirmhiremoreorlesslabor?
Why?
e.IfL=7,shouldfirmhiremoreorlesslabor?
LYMPL00n.a.110102199327843475406645574948523954210551CHAPTER3NationalIncomeslide25MPLandthedemandforlaborEachfirmhireslaboruptothepointwhereMPL=W/P.UnitsofoutputUnitsoflabor,LMPL,LabordemandRealwageQuantityoflabordemandedCHAPTER3NationalIncomeslide26TheequilibriumrealwageTherealwageadjuststoequatelabordemandwithsupply.UnitsofoutputUnitsoflabor,LMPL,LabordemandequilibriumrealwageLaborsupplyCHAPTER3NationalIncomeslide27DeterminingtherentalrateWehavejustseenthatMPL=W/P.ThesamelogicshowsthatMPK=R/P:
diminishingreturnstocapital:
MPKasKTheMPKcurveisthefirmsdemandcurveforrentingcapital.FirmsmaximizeprofitsbychoosingKsuchthatMPK=R/P.CHAPTER3NationalIncomeslide28Theequilibriumrealren