宏观经济学Lecture 4-Chapter 8nppt课件.ppt

《宏观经济学Lecture 4-Chapter 8nppt课件.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、Chapter8ATwo-PeriodModel:TheConsumption-SavingsDecisionandRicardianEquivalentTheoremChong-EnBaiandBinzhenWuOutlineConsumer’sintertemporaldecisions:consumptionandsavingsdecisionsHowthechoicesreacttothechangesinincomeandchangesininterestrateGovernmentCompetitiveequilibriumforaneconomywithoutfi

2、rm(investment)RicardianEquivalenceTheoremChangetheassumptionofthemodelDiscussionWhatdoyouthinkarethefactorsthataffectsavingsdecision?Howdoyoumodelconsumers’savingsdecisioninasimpleway?ModelSetupIrvingFisher:developedthemodelwithwhicheconomistsanalyzehowrational,forward-lookingconsumersmakein

3、tertemporalchoices.Actors:consumers,firms,governmentTwoperiods:intertemporaldecisionsConsumersmakeconsumption-savingsdecisions,whichconsiderstrade-offbetweencurrentandfutureconsumptionsFirmsmakeinvestmentdecisions,consideringtrade-offbetweencurrentandfutureprofits(ch.9)Governmentconsiderstra

4、de-offbetweencurrentandfuturetaxesConsumers,firmsandgovernmentcansaveorborrowintheformofrisk-freebondsatrealinterestrater.Consumer’sProblemAssumptionConsumersreceiveexogenousincome(Weabstractawayfromdecisionaboutlaborsupply)Lump-sumtaxtinthecurrentperiod,t’inthefutureperiodConsumersstartwith

5、noassets*Realinterestrateisthesameforlendingandborrowing.Consumer’sProblem–BudgetConstraintFirstperiod:c+s=y-tSecondperiod:s’=0;c’=y’-t’+(1+r)sWewanttofirstfocusonthechoicesbetweencandc’:considerthelifetimebudgetconstraintbysubstitutingsawayThepresentvalueofconsumptionisequaltothepresentvalu

6、eoflifetimedisposableincomePresentvalueisthevalueoffuturedollaramountintoday’stermsConsumer’sProblem–BudgetConstraint1/(1+r)istherelativepriceoffutureconsumptiongoodsintermsofcurrentconsumptiongoods.1/(1+r)isalsocalledthediscountfactor.Itconvertsquantitiesofgoods(ordollaramount)tomorrowintot

7、heirvalueinthepresent.Thediscountfactor<1,implyingonedollartomorrowisworthlessthanonedollartoday.1+ristherelativepriceofthecurrentconsumptiongoodsintermsoffutureconsumptiongoods.Figure8.1Consumer'sLifetimeBudgetConstraintc’=–(1+r)c+we(1+r)Consumer’