克鲁格曼国际经济学答案

Chapter21.Homehas1200unitsoflaboravailable.Itcanproducetwogoods,applesandbananas.Theunitlaborrequirementinappleproductionis3,whileinbananaproductionitis2.a.Graphouttheproductionpossibilitiesfrontier:b.Whatistheopportunitycostofapplesintermsofbananas?5.1=LbLaaac.Intheabsenceoftrade,whatwouldthepriceofapplesintermsofbananasbe?Intheabsenceoftrade,sincelaboristheonlyfactorofproductionandsupplydecisionsaredeterminedbytheattemptsofindividualstomaximizetheirearningsinacompetitiveeconomy,onlywhenLbLaba/aa/PP=willbothgoodsbeproduced.So1.5/PPba=2.Homeisasdescribedinproblem1.Thereisnowalsoanothercountry,Foreign,withalaborforceof800.Foreign’sunitlaborrequirementinappleproductionis5,whileinbananaproductionitis1.a.GraphForeign’sproductionpossibilitiesfrontier:b.3.Nowsupposeworldrelativedemandtakesthefollowingform:Demandforapples/demandforbananas=priceofbananas/priceofapples.a.Graphtherelativedemandcurvealongwiththerelativesupplycurve:abba/PP/DD=∵Whenthemarketachievesitsequilibrium,wehave1ba(DD-**=++=babbaaPPQQQQ∴RDisahyperbolaxy1=b.Whatistheequilibriumrelativepriceofapples?TheequilibriumrelativepriceofapplesisdeterminedbytheintersectionoftheRDandRScurves.RD:yx1=RS:5]5,5.1[5.1],5.0(5.05.0,0[=∈=⎪⎩⎪⎨⎧+∞∈=∈yyyxxx∴25.0==yx∴2/=bPaPeec.Describethepatternoftrade.∵babeaebaPPPPPP///>>**∴Inthistwo-countryworld,Homewillspecializeintheappleproduction,exportapplesandimportbananas.Foreignwillspecializeinthebananaproduction,exportbananasandimportapples.d.ShowthatbothHomeandForeigngainfromtrade.InternationaltradeallowsHomeandForeigntoconsumeanywherewithinthecoloredlines,whichlieoutsidethecountries’productionpossibilityfrontiers.Andtheindirectmethod,specializinginproducingonlyoneproductionthentradewithothercountry,isamoreefficientmethodthandirectproduction.Intheabsenceoftrade,Homecouldgainthreebananasbyforegoingtwoapples,andForeigncouldgainbyoneforegoingfivebananas.Tradeallowseachcountrytotradetwobananasforoneapple.HomecouldthengainfourbananasbyforegoingtwoappleswhileForeigncouldgainoneapplebyforegoingonlytwobananas.SobothHomeandForeigngainfromtrade.4.Supposethatinsteadof1200workers,Homehad2400.Findtheequilibriumrelativeprice.WhatcanyousayabouttheefficiencyofworldproductionandthedivisionofthegainsfromtradebetweenHomeandForeigninthiscase?RD:yx1=RS:5]5,5.1[5.1],1(11,0[=∈=⎪⎩⎪⎨⎧+∞∈=∈yyyxxx∴5.132==yx∴5.1/=bPaPeeInthiscase,Foreignwillspecializeinthebananaproduction,exportbananasandimportapples.ButHomewillproducebananasandapplesatthesametime.AndtheopportunitycostofbananasintermsofapplesforHomeremainsthesame.SoHomeneithergainsnorlosesbutForeigngainsfromtrade.5.SupposethatHomehas2400workers,buttheyareonlyhalfasproductioninbothindustriesaswehavebeenassuming,Constructtheworldrelativesupplycurveanddeterminetheequilibriumrelativeprice.Howdothegainsfromtradecomparewiththoseinthecasedescribedinproblem4?Inthiscase,thelaborisdoubledwhiletheproductivityoflaborishalved,sothe"effectivelabor"remainsthesame.Sotheanswerissimilartothatin3.AndbothHomeandForeigncangainfromtrade.ButForeigngainslessercomparewiththatinthecase4.6.”Koreanworkersearnonly$2.50anhour;ifweallowKoreatoexportasmuchasitlikestotheUnitedStates,ourworkerswillbeforceddowntothesamelevel.Youcan’timporta$5shirtwithoutimportingthe$2.50wagethatgoeswithit.”Discuss.Infact,relativewagerateisdeterminedbycomparativeproductivityandtherelativedemandforgoods.Korea’slowwagereflectsthefactthatKoreaislessproductivethantheUnitedStatesinmostindustries.Actually,tradewithalessproductive,lowwagecountrycanraisethewelfareandstandardoflivingofcountrieswithhighproductivity,suchasUnitedStates.Sothispauperlaborargumentiswrong.7.JapaneselaborproductivityisroughlythesameasthatoftheUnitedStatesinthemanufacturingsector(higherinsomeindustries,lowerinothers,whiletheUnitedStates,isstillconsiderablymoreproductiveintheservicesector.Butmostservicesarenon-traded.SomeanalystshavearguedthatthisposesaproblemfortheUnitedStates,becauseourcomparativeadvantageliesinthingswecannotsellonworldmarkets.Whatiswrongwiththisargument?Thecompetitiveadvantageofanyindustrydependsonboththerelativeproductivitiesoftheindustriesandtherelativewagesacrossindustries.Sotherearefouraspectsshouldbetakenintoaccountbeforewereachconclusion:boththeindustriesandservicesectorsofJapanandU.S.,notjustthetwoservicesectors.Sothisstatementdoesnotbadeonthereasonablelogic.8.AnyonewhohasvisitedJapanknowsitisanincrediblyexpensiveplace;althoughJapaneseworkersearnaboutthesameastheirU.S.counterparts,thepurchasingpoweroftheirincomesisaboutone-thirdless.Extendyourdiscussingfromquestion7toexplainthisobservation.(Hint:Thinkaboutwagesandtheimpliedpricesofnon-tradegoods.TherelativehigherpurchasingpowerofU.S.issustainedandmaintainedbyitsconsiderablyhigherproductivityinservices.Becausemostofthoseservicesarenon-traded,Japanesecouldnotbenefitfromthoselowerservicecosts.AndU.S.doesnothavetofacealowerinternationalpriceofservices.SothepurchasingpowerofJapaneseisjustone-thirdoftheirU.S.counterparts.9.Howdoesthefactthatmanygoodsarenon-tradedaffecttheextentofpossiblegainsfromtrade?Actuallythegainsfromtradedependedontheproportionofnon-tradedgoods.Thegainswillincreaseastheproportionof