12重访开放经济蒙代尔-弗莱明模型与汇率制度

CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide0重访开放经济：蒙代尔-弗莱明模型与汇率制度CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide1LearningobjectivesLearningobjectivesMundell-Fleming模型:小型开放经济的IS-LM模型利率差别的成因与效应固定汇率vs.浮动汇率的争论小型开放经济的总需求曲线CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide2TheTheMundellMundell--FlemingModelFlemingModel关键假设:资本完全流动的小型开放经济r=r*产品市场均衡---IS*曲线:()()()*YCYTIrGNXe其中e=名义汇率=外国货币/单位本国货币CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide3TheTheIS*IS*curve:GoodsMarketcurve:GoodsMarketEqEq’’mmIS*曲线是给定r*的值画出来的.斜率的直觉:YeIS*()()()*YCYTIrGNXeeNXYCHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide4TheTheLM*LM*curve:MoneyMarketcurve:MoneyMarketEqEq’’mmLM*曲线是给定r*的值画出来的垂直，因为:给定r*,只有唯一的Y使得货币需求等于货币供给，不管e是多少.YeLM*(,)*MPLrYCHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide5EquilibriumintheEquilibriumintheMundellMundell--FlemingmodelFlemingmodelYeLM*(,)*MPLrYIS*()()()*YCYTIrGNXe均衡汇率均衡收入水平CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide6Floating&fixedexchangeratesFloating&fixedexchangerates在floatingexchangerates下,e可随着经济条件变化而波动.相对的,在fixedexchangerates下,中央银行以事先确定的价格买卖外汇.现在考虑财政政策，货币政策与贸易政策:先讨论浮动汇率体系,然后再讨论固定汇率体系CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide7FiscalpolicyunderfloatingexchangeratesFiscalpolicyunderfloatingexchangeratesYe(,)*MPLrY()()()*YCYTIrGNXeY1e11*LM1*IS2*ISe2在任一给定的e,财政扩张提高Y,使IS*曲线右移结果:e0,Y=0CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide8LessonsaboutfiscalpolicyLessonsaboutfiscalpolicy在一个完全资本流动的小型开放经济中,财政政策对实际GDP完全没有影响.“挤出”•封闭经济:财政政策通过提高利率挤出投资•小型开放经济:财政政策通过汇率上升挤出净出口CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide9Mon.policyunderfloatingexchangeratesMon.policyunderfloatingexchangeratesYe(,)*MPLrY()()()*YCYTIrGNXee1Y11*LM1*ISY22*LMe2M的增加使得LM*曲线右移，因为Y必须上升以重建货币市场的均衡结果:e0,Y0CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide10LessonsaboutmonetarypolicyLessonsaboutmonetarypolicy货币政策通过影响总需求的一个（或多个）构成来影响产出:封闭经济:MrIY小型开放经济:MeNXY扩张性的货币政策不会提高世界的总需求它将国外需求转化为国内需求.因此,国内收入与就业的增长是以国外收入与就业降低为代价的CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide11TradepolicyunderfloatingexchangeratesTradepolicyunderfloatingexchangerates(,)*MPLrY()()()*YCYTIrGNXeYee1Y11*LM1*IS2*ISe2在任一给定的e,关税或配额减少进口，增加NX,并使IS*右移结果:e0,Y=0CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide12LessonsabouttradepolicyLessonsabouttradepolicy进口限制不能降低贸易赤字.即便NX没有变动,贸易也更少:–贸易限制减少了进口–汇率上升减少了出口更少的贸易意味着更少的‘贸易收益’对特定产品的进口限制挽救了生产同类产品的国内行业的就业机会,但却破坏了出口部门的就业.因此,进口限制不能增加总就业更糟的是,进口限制导致“部门转移,”这将导致摩擦性失业CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide13FixedexchangeratesFixedexchangerates在固定汇率制度下,一国中央银行随时准备以事先确定的汇率买、卖外汇.在Mundell-Fleming模型中,中央银行使LM*曲线移动以保证e维持在预先确定的比率上.这种制度将名义汇率固定下来.在长期,当价格具有弹性时,即便名义汇率固定,实际汇率也可以变动CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide14FiscalpolicyunderfixedexchangeratesFiscalpolicyunderfixedexchangeratesYeY1e11*LM1*IS2*IS在浮动汇率制下,财政扩张会提高e.结果:e=0,Y0Y22*LM为了维持e不变,中央银行必须卖出本币,这增加了M并使得LM*右移.在浮动汇率制下,财政政策对产出没有影响.在固定汇率制下,财政政策非常有效地的影响产出CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide15Mon.policyunderfixedexchangeratesMon.policyunderfixedexchangerates2*LMM的增加会使LM*右移并降低e.YeY11*LM1*ISe1为了阻止e下降,中央银行必须买入本币,这会减少M并使LM*左移回到原来的位置.结果:e=0,Y=0在浮动汇率下,货币政策对改变产出非常有效.在固定汇率下,货币政策不能影响产出2*LMCHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide16TradepolicyunderfixedexchangeratesTradepolicyunderfixedexchangeratesYeY1e11*LM1*IS2*IS限制进口的政策给汇率e施加了向上的压力.结果:e=0,Y0Y22*LM为了维持e不上升,中央银行必须卖出本币,这提高了M并使LM*右移.在浮动汇率下,进口限制不影响Y或NX.在固定汇率下,进口限制增加Y与NX.但是,这些收益是以他国的代价为基础的,因为政策仅仅使得把国外需求转为国内需求CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide17MM--F:summaryofpolicyeffectsF:summaryofpolicyeffects000进口限制000货币扩张000财政扩张NXEYNXEY政策影响:固定浮动汇率制度:CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide18InterestInterest--ratedifferentialsratedifferentials有两个原因，使得r与r*之间可能存在差异国家风险:是指由于政治或者经济骚动引起的债务人违约拖欠借款的风险.债权人不得不要求更高的利息来补偿他们贷款出去所承担的风险.预期的汇率变化:如果一个国家的汇率预期下降,那么他的借款人必须支付更高的利率来补偿预期货币贬值给贷款人带来的损失CHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide19DifferentialsintheMDifferentialsintheM--FmodelFmodel其中是风险贴水.替代IS*与LM*方程的r:(,)*MPLrY()()()*YCYTIrGNXe*rrCHAPTER12CHAPTER12AggregateDemandintheOpenEconomyAggregateDemandintheOpenEconomyslide20TheeffectsofanincreaseinTheeffectsofanincreasein2*LMIS*左移,因为rIYeY1e11*LM1*ISLM*右移,因为r(M/P)d,所以Y必须上升来重建货币市场的均衡结果:e0,Y02*ISe2Y2CHAPTER12CHAPTER12AggregateDemandintheO