Chapter 3 Consumption and Investment 英文版的宏观经济学 萨缪尔森版 教学课件.ppt

《Chapter 3 Consumption and Investment 英文版的宏观经济学 萨缪尔森版 教学课件.ppt》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、Chapter3ConsumptionandInvestment1ConsumptionandSaving2TheNationalConsumptionBehavior3InvestmentWhatAretheMajorForcesAffectingConsumptionandInvestment?1ConsumptionandSaving1.1IndividualConsumptionandSavingIncome=Consumption＋SavingDisposableincomeisanimportantdeterminantofcon

2、sumptionandsaving.※TheConsumptionFunctionC=f（Y）C=α+βYα:AutonomousConsumptionβ：SlopeoftheCurveY:DIβY:InducedConsumption※TheSavingFunctionTheSavingFunctionIstheMirrorImageoftheConsumptionFunctions=f(DI)S=Y－C＝Y－（α+βY）S=－α+(1－β)YThemarginalpropensitytoconsume(MPC)istheextraamou

3、ntthatpeopleconsumewhentheyreceiveanextradollarofdisposableincome.※TheMarginalPropensitytoConsume(MPC)MPC(β)＝C/YTheSlopeoftheConsumptionFunctionIsItsMPCMPC(β)＝C/YThemarginalpropensitytosave(MPS)istheextrasavinggeneratedbyanextradollarofdisposableincome.※TheMarginalPrope

4、nsitytoSave(MPS)MPS=ΔS/ΔYMPC＋MPS=12TheNationalConsumptionBehavior2.1DeterminantsofConsumption※CurrentDisposableIncome:APC=C/YMPC=C/YC=α+βY,α>0,0<β<1APC=C/Y=α/Y＋βC=α+βY1929－1940，C=33.9＋0.8y1947－1956，C=41.2＋0.82yTheendofWorldWarⅡdidnotthrowUSAintoanotherdepression.Thesecula

5、r-stagnationhypothesisKuznetsfoundthattheMPCisfairlyconstantoverlongperiodoftime.Theconsumptionpuzzle:WhydidKeynes’sconjecturesholdupwellinthestudiesofhouseholddataandinthestudiesofshorttime-series,butfailwhenlongtime-serieswereexamined?※PermanentIncomeModelofconsumption◎Mo

6、del◎ExplanationIntheshortrun,fluctuationinincomearedominatedbytransitoryincome.APCfallsasincomerises.Inthelongrun,thevariationinincomecomesfromthepermanentcomponent.APCisconstant.◎PolicyImplication※TheLife-CycleModelofConsumption◎Model◎ExplanationCPolicyImplicationAprograml

7、ikesocialsecuritywillreducessaving.PrecautionarySavingTwoReasons:BequestMotiveTOSummarize:Disposableincomeisanimportantdeterminantofconsumption.APCfallsasincomerisesatleastintheshortrun.Cisinfluencedbypermanentincome.Aprogramlikesocialsecuritywillreducessaving.1.2TheNationa

8、lConsumptionFunctionC=f(Y)PersonalSavingRateHasDeclinedWhyhasAmericanpersonalsavin