精选-国际经济学克鲁格曼-教材答案.doc

ProblemsandAnswerstoChapter2Q1:CanadaandAustraliaare(mainly)English-speakingcountrieswithpopulationsthatarenottoodifferentinsize(Canada’sis60percentlarger).ButCanadiantradeistwiceaslarge,relativetoGDP,asAustralia’s.Whyshouldthisbethecase?加拿大和澳大利亚都是英语国家，两国的人口规模也相当（加拿大多60%），但是相对各自的GDP而言，加拿大的贸易额是澳大利亚的两倍，为什么如此？A1:AccordingtoGravityModel,GDPisnottheonlyfactortoexplainthevolumeoftradebetweentwocountries,becausedistanceisalsoanimportantfactor.Consideringthedistance,thetransportationcostofAustraliaisrelativelyhigherthanthatofCanada,sotheattractivenessoftradeisreduced.However,CanadaisclosetotheUSAwhichisalargeeconomywhileAustraliaisnotclosetoanylargeeconomy,makingCanadamoreopenwhileAustraliaismoreautarky.GDP不是解释两国贸易量的唯一重要因素，距离也是至关重要的因素之一。考虑到距离，澳大利亚的进出口运输成本相对更高，因此减少了贸易吸引力。因为加拿大与美国相邻，而澳大利亚不与任何一个大经济体相邻，这使得加拿大更加开放，而澳大利亚更加自给自足。Q2:MexicoandBrazilhaveverydifferenttradingpatterns.MexicotradesmainlywiththeUnitedStates,BraziltradesaboutequallywiththeUnitedStatesandwiththeEuropeanUnion;MexicodoesmuchmoretraderelativetoitsGDP.Explainthesedifferencesusingthegravitymodel.墨西哥和巴西各自的贸易模式不同。墨西哥主要与美国贸易，巴西与美国和欧盟的贸易量大致相当。墨西哥的贸易量相对其GDP而言很大。用引力模型解释这种现象。A2:MexicoisclosetotheUnitedStates,butisveryfarfromtheEuropeanUnion,soMexico’svalueoftradewiththeUnitedStatesislarge.BrazilisfarfromboththeUnitedStatesandEuropeanUnion,thus,Brazil’svolumeoftradewiththeUnitedStatesandwiththeEuropeanUnionisgenerallyequivalent.Mexico’svolumeoftradeislargerthanBrazil’s,fortworeasons:oneisthatMexicoisadjacenttotheUnitedStateswhichisalargeeconomy;theotheristhatMexicoisoneofthemembersofNAFTA.Brazilisfarfromanylargeeconomy,andthesizeoftheeconomyforthecountrieswhichhavesignedfreetradeagreementswithBrazilisrelativelysmall.墨西哥与美国毗邻，但是距离欧盟很远，因此它与美国的贸易量很大。巴西离美国和欧盟都很远，因此巴西与美国和欧盟的贸易量大致相当。墨西哥贸易量比巴西大，其原因一方面由于墨西哥离大经济体美国近，另一方面由于它是北美贸易协定的成员国之一。巴西远离任何一个大经济体，与它签订自由贸易协定的国家经济规模都比较小。Q3:Equation(2.1)saysthattradebetweenanytwocountriesisproportionaltotheproductoftheirGDPs.DoesthismeanthattheGDPofeverycountryintheworldweretoincreaseby50%,worldt