《國際貿(mào)易（第七版）》Chap004

ExtensionsandTestsoftheClassicalModelofTradeChapter4LearningObjectivesDemonstratehowwages,productivity,andexchangeratesaffecttradepatterns.Examinetheimplicationsofextendingthebasicmodelofcomparativeadvantage.Showthatreal-worldtradepatternsareconsistentwithunderlyingcomparativeadvantage.AddingMoneytotheClassicalModelSupposeamoneyeconomyinsteadofabartereconomy.Awagerateforeachcountry,statedinthatcountry’scurrency(e.g.,inU.S.$2perhr.,intheU.K.,￡1perhr.).Anexchangeratethatrelatesthecountries’currencies(e.g.,$1=￡1).AnExample4-4AnExample4-5AddingMoneytotheClassicalModel:AnExampleTheU.S.willexportwheat,sinceitcanproducewheatforalowerprice($4,ascomparedwith$6).TheU.K.willexportcloth,sinceitcanproduceclothforalowerprice($4,ascomparedwith$6).TheExportConditionCountry1shouldexportgoodjwhen:a1j*W1*e<a2j*W2,wherea1janda2jarethelaborrequirements/hrtoproducegoodjincountries1and2W1andW2arethewagerates/hrincountries1and2eiscountry1’sexchangerate(#ofcountry2’scurrencyunitsper1ofcountry1’s).TheExportConditionCountry1shouldexportgoodjwhen:a1j*W1*e<a2j*W2.Thatis,whencountry1’sgoodjpriceislowerthan2’s,statedinacommoncurrency.Therefore,thepatternoftradeisdeterminedbyrelativelaborefficiency,relativewagerates,andtheexchangerate.TheExportConditionCountryAshouldexportgoodjwhen:a1j*W1*e<a2j*W2.Let’sre-writethisasfollows:CountryAshouldexportgoodjwhen: a1j/a2j<W2/(W1*e).WageRateLimitsAsCountry1’swagerategoesuprelativetoCountry2’s,Country1findsithardertosellitsexportstoCountry2.AsCountry1’swagerategoesdownrelativetoCountry2’s,Country1islessinterestedinimportingfromCountry2.WageRateLimits:AnExample4-11WageRateLimits:AnExample4-12WageRateLimits:AnExampleShouldtheU.S.(Country1)exportwheat? Itshouldifa1j/a2j<W2/(W1*e).Since2/6<1/(3*0.5),theU.S.shouldexportwheat[or:theU.S.wheatpriceis$6;theU.K.wheatpriceis￡6=$12].It’seasytoshowthattheU.K.shouldexportcloth.WageRateLimits:AnExampleWhatiftheU.S.wagerateroseto$6?WageRateLimits:AnExample4-15WageRateLimits:AnExampleNowtheU.S.wheatpriceisthesameastheU.K.’s,ifwestatetheminacommoncurrency.WageRateLimits:AnExampleNowtheU.S.wheatpriceisthesameastheU.K.’s,ifwestatetheminacommoncurrency.Therefore,ifthewagerateintheU.S.shouldriseabove$6,theU.K.willnolongerbuyU.S.wheat(tradewillcease).WageRateLimits:AnExampleWhatifinsteadtheU.S.wageratefellto$2.67?WageRateLimits:AnExample4-19WageRateLimits:AnExampleWhatiftheU.S.wageratefellto$2.67?NowtheU.S.clothpriceisthesameastheU.K.’s,ifwestatetheminacommoncurrency($8).Therefore,ifthewagerateintheU.S.shouldfallbelow$2.67,theU.S.willnolongerbuyU.K.cloth(tradewillcease).CalculatingWageRateLimitsUsingtheExportConditionSolvetheexportconditionforW1,forgoodX.SolvetheexportconditionforW1,forgoodY.ThesewillgiveyouCountryA’swageratelimits.CalculatingWageRateLimitsUsingtheExportConditiona1j/a2j<W2/(W1*e)Forwheat:2/6=1/(W1*0.5)→W1=6Forcloth:3/4=1/(W1*0.5)→W1=2.67Country2’sWageRateLimitsChangesinCountry2’swageratesalsocanaffectthepatternoftrade.If2’swagerisestoomuch,theywillnotbeabletoexportanymore.If2’swagefallstoomuch,2willnolongerwishtoimport.SolvetheexportconditionforW2foreachgood.ExchangeRateLimitsIfCountry1’scurrencyappreciates,importswillseemcheaperandexportsmoreexpensive.If1’scurrencyappreciatesenough,Awillnolongerbeabletoexport.If1’scurrencydepreciatesenough,Awillnolongerwishtoimport.Solveexportconditionfore.MoreThanTwoGoodsHavingmorethantwogoodshasnoeffectonthebasicClassicalmodel.MoreThanTwoGoods:AnExample4-26MoreThanTwoGoodsTheexportconditioncanstillbeused.Perhapsitisbettertoputalloftheproductsinascendingorder:MoreThanTwoGoods:AnExample4-28MoreThanTwoGoods:AnExampleSupposetheexchangerateisstill$1=￡0.5(thatis,e=0.5).ThenW2/(W1*e)=1/(3*0.5)=0.67Usethisasa“pointer”:Country1shouldexporteverythingtotheleftofthepointer.MoreThanTwoGoods:AnExampleW2/(W1*e)=0.674-30MoreThanTwoGoods:AnExampleIftheU.S.wagerateweretofall,thepointerwouldmovetotheright,andtheU.S.wouldstartexportinggoodsitpresentlyimports.IftheU.S.wageweretorise,thepointerwouldmoveleft.ChangesintheU.K.’swage,ortheexchangerate,wouldalsomovethepointerandthusaffectthepatternoftrade.AddingTransportationCostsAssume:alltransportationcostsarepaidbytheimporter.transportationcostsaremeasuredintermsoftheirlaborcontent.Country1’sexportcondition: (a1j+trj)/a2j<W2/(W1*e)Supposeinpreviousexamplet-costsare1laborhour.TransportationCosts:AnExampleW2/(W1*e)=0.674-33TransportationCosts:AnExampleNoticethatalthoughtheU.K.hasacomparativeadvantageincloth,itwillnolongerexportthisproduct,since(a1j+trj)/a2j=0.6<W2/(W1*e)=0.67.

Intherealworld,someproductswithhight-costs(e.g.,bulkyones)arenottraded.MoreThanTwoCountriesHavingmorethantwocountriesalsohasnoeffectonthebasicClassicalmodel.MoreThanTwoCountries:AnExampleMoreThanTwoCountries:AnExampleU.K.hastheCAincloth,sinceitsautarkyclothpriceisthelowest.U.S.hastheCAinwheat,sinceitsautarkywheatpriceisthelowest.MoreThanTwoCountries:AnExampleIfthetermsoftradeare1C=1.8W(or:1W=.55C),thentheU.S.willexportwheat(becausetheinternationalwheatpriceisgreaterthantheU.S.domesticprice).FranceandtheU.K.willexportcloth(becausetheinternationalcl