宏观经济学---曼昆chap03PPT文件格式下载.ppt
《宏观经济学---曼昆chap03PPT文件格式下载.ppt》由会员分享,可在线阅读,更多相关《宏观经济学---曼昆chap03PPT文件格式下载.ppt(63页珍藏版)》请在冰豆网上搜索。
thephysicalandmentalefforts(time)ofworkers-Weassumethat1)KandLasgiven,i.e.,fixed,and2)fullyutilized(nounemployment).Cf)Land,Materials,Energy,CHAPTER3NationalIncomeTheproductionfunctionldenotedY=F(K,L)lshowshowmuchoutput(Y)theeconomycanproducefromKunitsofcapitalandLunitsoflaborlreflectstheeconomysleveloftechnologylexhibitsconstantreturnstoscale(closelyrelatedtoincomedistribution!
)CHAPTER3NationalIncomeReturnstoscale:
AreviewInitiallyY1=F(K1,L1)Scaleallinputsbythesamefactorz:
K2=zK1andL2=zL1(e.g.,ifz=1.25,thenallinputsareincreasedby25%)Whathappenstooutput,Y2=F(K2,L2)?
lIfconstantreturnstoscale,Y2=zY1lIfincreasingreturnstoscale,Y2zY1lIfdecreasingreturnstoscale,Y20CHAPTER3NationalIncomeExample2decreasingreturnstoscaleforanyz1CHAPTER3NationalIncomeExample3increasingreturnstoscaleforanyz1CHAPTER3NationalIncomeAssumptionsofthemodel1.Technologyisfixed.2.TheeconomyssuppliesofcapitalandlaborarefixedatCHAPTER3NationalIncomeDeterminingGDPOutputisdeterminedbythefixedfactorsuppliesandthefixedstateoftechnology:
IncreaseinKandLandimprovementsintheproductiontechnologyleadtogrowthintheeconomysoutput(Chapter7and8).CHAPTER3NationalIncomeThedistributionofnationalincomeldeterminedbyfactorprices,thepricesperunitthatfirmspayforthefactorsofproductionmwage=priceofLmrentalrate=priceofKCHAPTER3NationalIncomeNotationW=nominalwageR=nominalrentalrateP=priceofoutputW/P=realwage(measuredinunitsofoutput)R/P=realrentalrateCHAPTER3NationalIncomeHowfactorpricesaredeterminedlFactorpricesaredeterminedbysupplyanddemandinfactormarkets.lRecall:
Supplyofeachfactorisfixed.lWhataboutdemand?
Figure3.2HowaFactorofProductionIsCompensatedCHAPTER3NationalIncomeDemandforlaborlAssumemarketsarecompetitive:
eachfirmtakesW,R,andPasgiven.lBasicidea:
Afirmusesfactorsofproductiontomaximizeprofit.lProfit=Revenue-LaborCosts-CapitalCosts=PYWLRK=PF(K,L)WL-RKCHAPTER3NationalIncomeMarginalproductoflabor(MPL)ldefinition:
Theextraoutputthefirmcanproduceusinganadditionalunitoflabor(holdingotherinputsfixed):
MPL=F(K,L+1)F(K,L)CHAPTER3NationalIncomeExercise:
Compute&
graphMPLa.DetermineMPLateachvalueofL.b.Graphtheproductionfunction.c.GraphtheMPLcurvewithMPLontheverticalaxisandLonthehorizontalaxis.LYMPL00n.a.110?
219?
3278434?
540?
645?
749?
852?
954?
1055?
CHAPTER3NationalIncomeAnswers:
CHAPTER3NationalIncomeYoutputMPLandtheproductionfunctionLlabor1MPL1MPL1MPLAsmorelaborisadded,MPLSlopeoftheproductionfunctionequalsMPLCHAPTER3NationalIncomeDiminishingmarginalproductlAsafactorinputisincreased,itsmarginalproductfalls(otherthingsequal).lIntuition:
SupposeLwhileholdingKfixedfewermachinesperworkerlowerworkerproductivityCHAPTER3NationalIncomeCheckyourunderstanding:
lWhichoftheseproductionfunctionshavediminishingmarginalreturnstolabor?
CHAPTER3NationalIncomeDemandforLaborlFirmsgoal:
maximizeprofits.lQ.Hireadditionalunitoflaborornot?
lA.Lookatitseffectsonprofit!
lCompareextrarevenuefromextraoutputproducedbytheextraunitoflabortoextracostofhigherspendingonwagesCHAPTER3NationalIncomeDemandforLaborlExtrarevenuefromextraoutputproducedbytheextraunitoflabor=MPL*PlExtracostofhigherspendingonwages=WlChangeofProfit=MPL*PWlFirmscontinuetohireadditionalunitoflaborif0.Theystopif=0.lHence,wegetlorCHAPTER3NationalIncomeMPLandthedemandforlaborEachfirmhireslaboruptothepointwhereMPL=W/P.UnitsofoutputUnitsoflabor,LMPL,LabordemandRealwageQuantityoflabordemandedCHAPTER3NationalIncomeTheequilibriumrealwageTherealwageadjuststoequatelabordemandwithsupply.UnitsofoutputUnitsoflabor,LMPL,LabordemandequilibriumrealwageLaborsupplyCHAPTER3NationalIncomeExercise(part2)Suppo