马歇尔勒纳条件和J曲线效应推导.ppt

Primaryquestion Underwhatcircumstancesdoesdevaluationimprovethetradebalance TB Secondaryquestion Ifthecurrencyfloats i e noforeignexchangeinterventionbythecentralbank howmuchmusttheexchangerate E changetoclearTBbyitself i e withnooffsettingcapitalflows Model ElasticitiesApproachKeyderivation Marshall LernerCondition LECTURE1 DEVALUATION THETRADEBALANCE GOODSMARKETPRICINGINOPEN ECONOMYMODELS ALTERNATIVEASSUMPTIONS GOODSMARKETPRICINGINOPEN ECONOMYMODELS ALTERNATIVEASSUMPTIONS continued GOODSMARKETPRICINGINOPEN ECONOMYMODELS ALTERNATIVEASSUMPTIONS continued TheMarshall LernerCondition Underwhatconditionsdoesdevaluationimprovethetradebalance Wecanexpressthetradebalanceeitherintermsofforeigncurrency TB e g ifweareinterestedindeterminingthenetsupplyofforeignexchangeinthefxmarket balanceofpayments Orintermsofdomesticcurrency TBe g ifweareinterestedinnetexportsasacomponentofGDP C I G TB WewillfocusonTB here andonTBinProb Set1 HowtheExchangeRate E InfluencesBoP SupplyoffxdeterminedbyEXPORTearnings DemandforfxdeterminedbyIMPORTspending 2 PCP Priceintermsofproducer scurrency Supplyelasticity Domesticfirmsset Foreignfirmsset 3 Completeexchangeratepassthrough PriceofXinforeigncurrency E PriceofImportsindomesticcurrency E 4 Demand adecreasingfunctionofpriceinconsumer scurrency X XD E M MD E Netsupplyoffx TBexpressedinforeigncurrency TB E XD E MD E Nocapitalflowsortransfers BoP TB DerivationoftheMarshall LernerCondition TB 1 E XD E MD E Differentiate MultiplybyE2 X Thisquantity 0iffDefineelasticities Theconditionbecomes Assumeforsimplicitywestartfromaninitialpositionofbalancedtrade EM X ThentheinequalityreducestoThisistheMarshallLernercondition Iftheinitialpositionistradedeficit orsurplus thenthenecessaryconditionfordTB dE 0willbeabiteasier orharder fortheelasticitiestomeet Dodevaluationsimprovethetradebalanceinpractice