第二章勞動(dòng)生產(chǎn)率和比較優(yōu)勢(shì)李嘉圖模型

第二章勞動(dòng)生產(chǎn)率和比較優(yōu)勢(shì)：李嘉圖模型導(dǎo)論比較優(yōu)勢(shì)的概念單一要素經(jīng)濟(jì)單一要素經(jīng)濟(jì)中的貿(mào)易對(duì)比較優(yōu)勢(shì)的誤解多商品中的比較優(yōu)勢(shì)運(yùn)輸費(fèi)用和非貿(mào)易品對(duì)李嘉圖模型的實(shí)證研究總結(jié)1國(guó)家之間進(jìn)行國(guó)際貿(mào)易基于兩個(gè)基本的原因：一是差異：氣候、資源、技術(shù)等二是生產(chǎn)中的規(guī)模經(jīng)濟(jì)scaleeconomies(規(guī)模經(jīng)濟(jì))李嘉圖模型（TheRicardianmodel

）基于各國(guó)間技術(shù)差異技術(shù)差異反映在勞動(dòng)生產(chǎn)率上（productivityoflabor）.導(dǎo)論2美國(guó)情人節(jié)的例子。OnValentine’sDaytheU.S.demandforrosesisabout10million（100萬(wàn)支）

roses.美國(guó)在冬天種植玫瑰比較困難：加熱的溫室其投入的資源是比較多的（能源、勞動(dòng)力、資本）這些資源也可以用來(lái)生產(chǎn)其他商品，如計(jì)算機(jī).2-1比較優(yōu)勢(shì)的概念3OpportunityCost（機(jī)會(huì)成本）Theopportunitycostofroses（A)intermsofcomputers（B)isthenumberofcomputers（B)thatcouldbeproducedwiththesameresourcesasagivennumberofroses（A).以商品B衡量生產(chǎn)商品A的機(jī)會(huì)成本，就是生產(chǎn)一定數(shù)量商品A所消耗的資源所能生產(chǎn)商品B的數(shù)量。例：生產(chǎn)1000萬(wàn)支玫瑰的機(jī)會(huì)成本是10萬(wàn)臺(tái)計(jì)算機(jī)；而生產(chǎn)10萬(wàn)計(jì)算機(jī)的機(jī)會(huì)成本是1000萬(wàn)支玫瑰。

更為準(zhǔn)確地說(shuō)，生產(chǎn)一支玫瑰的機(jī)會(huì)成本是？臺(tái)計(jì)算機(jī)；而生產(chǎn)一臺(tái)計(jì)算機(jī)的機(jī)會(huì)成本是？支玫瑰。ComparativeAdvantage（比較優(yōu)勢(shì)）Acountryhasacomparativeadvantageinproducingagoodiftheopportunitycostofproducingthatgoodintermsofothergoodsislowerinthatcountrythanitisinothercountries.如果一國(guó)生產(chǎn)一種產(chǎn)品的機(jī)會(huì)成本（用其他商品衡量）低于其他國(guó)家生產(chǎn)該種產(chǎn)品的機(jī)會(huì)成本，則該國(guó)在生產(chǎn)此種產(chǎn)品上具有比較優(yōu)勢(shì)。4假定美國(guó)生產(chǎn)100支玫瑰的資源可以用來(lái)生產(chǎn)10萬(wàn)臺(tái)計(jì)算機(jī)。假定在南美生產(chǎn)100支玫瑰的資源可以用來(lái)生產(chǎn)3萬(wàn)臺(tái)計(jì)算機(jī).這就假定南美比美國(guó)的勞動(dòng)生產(chǎn)率更低。5如果每個(gè)美國(guó)均專業(yè)化生產(chǎn)機(jī)會(huì)成本更低的商品，則貿(mào)易使雙方受益。在南美玫瑰的機(jī)會(huì)成本更低，而美國(guó)計(jì)算機(jī)的機(jī)會(huì)成本更低。從貿(mào)易中獲利可以從雙方計(jì)算機(jī)和玫瑰產(chǎn)量的變化得到。6Table2-1:產(chǎn)量的變化7玫瑰的機(jī)會(huì)成本計(jì)算機(jī)的機(jī)會(huì)成本UnitedStates0.01100SouthAmerica0.0033338TheexampleinTable2-1illustratestheprincipleofcomparativeadvantage:Ifeachcountryexportsthegoodsinwhichithascomparativeadvantage(loweropportunitycosts),thenallcountriescaninprinciplegainfromtrade.Whatdeterminescomparativeadvantage?Answeringthisquestionwouldhelpusunderstandhowcountrydifferencesdeterminethepatternoftrade(whichgoodsacountryexports).（RicardianModel）92-2AOne-FactorEconomyAssumethatwearedealingwithaneconomy(whichwecallHome).Inthiseconomy（五個(gè)假定條件）Laboristheonlyfactorofproduction.（一種要素:勞動(dòng)力）Onlytwogoods(saywineandcheese)areproduced.（兩種商品）Thesupplyoflaborisfixedineachcountry.（勞動(dòng)要素供應(yīng)不變）Theproductivityoflaborineachgoodisfixed.（勞動(dòng)生產(chǎn)率不變）Perfectcompetitionprevailsinallmarkets.（完全競(jìng)爭(zhēng)）10Theconstantlaborproductivityismodeledwiththespecificationofunitlaborrequirements:Theunitlaborrequirement（單位位產(chǎn)品品勞動(dòng)動(dòng)投入入）isthenumberofhoursoflaborrequiredtoproduceoneunitofoutput.（單位位：人人小時(shí)時(shí)，person-hours）DenotewithaLWtheunitlaborrequirementforwine(e.g.ifaLW=2,thenoneneeds2hoursoflabortoproduceonegallonofwine).DenotewithaLCtheunitlaborrequirementforcheese(e.g.ifaLC=1,thenoneneeds1houroflabortoproduceapoundofcheese).總資源源為勞勞動(dòng)力力（L）Theeconomy’stotalresourcesaredefinedasL,thetotallaborsupply(e.g.ifL=120,thenthiseconomyisendowedwith120hoursoflaboror120workers).11ProductionPossibilities(生產(chǎn)能能力)Theproductionpossibilityfrontier(PPF，生產(chǎn)產(chǎn)可能能性邊邊界)ofaneconomyshowsthemaximumamountofagood(saywine)thatcanbeproducedforanygivenamountofanother(saycheese),andviceversa.（生產(chǎn)可可能性性邊界界：給定一一種產(chǎn)產(chǎn)品產(chǎn)產(chǎn)量時(shí)時(shí)，能能夠生生產(chǎn)另另外一一種產(chǎn)產(chǎn)品的的最大大可能能產(chǎn)量量）ThePPFofoureconomyisgivenbythefollowingequation:aLC×QC+aLW×QW≤L(2-1)Fromourpreviousexample,weget:QC+2QW≤12012L/aLWL/aLCFigure2-1:Home’’sProductionPossibilityFrontierAbsolutevalueofslopeequalsopportunitycostofcheeseintermsofwineFPHomewineproduction,QW,ingallonsHomecheeseproduction,QC,inpounds13RelativePricesandSupplyTheparticularamountsofeachgoodproducedaredeterminedbyprices.Therelativeprice(相對(duì)價(jià)價(jià)格)ofgoodX(cheese)intermsofgoodY(wine)istheamountofgoodY(wine)thatcanbeexchangedforoneunitofgoodX(cheese).Examplesofrelativeprices:IfapriceofacanofCokeis$0.5,thentherelativepriceofCokeistheamountof$thatcanbeexchangedforoneunitofCoke,whichis0.5.Therelativepriceofa$intermsofCokeis2cansofCokeperdollar.14DenotewithPCthedollarpriceofcheeseandwithPWthedollarpriceofwine.DenotewithwWthedollarwageinthewineindustryandwithwCthedollarwageinthecheeseindustry.(工資率率)：葡萄萄酒部部門工工資率率為PW/aWThenunderperfectcompetition,thenon-negativeprofitconditionimplies:IfPW/aW<wW,thenthereisnoproductionofQW.IfPW/aW=wW,thenthereisproductionofQW.IfPC/aC<wC,thenthereisnoproductionofQC.IfPC/aC=wC,thenthereisproductionofQC.15Theaboverelationsimplythatiftherelativepriceofcheese(PC/PW)exceedsitsopportunitycost(aLC/aLW),thentheeconomywillspecializeintheproductionofcheese.（當(dāng)當(dāng)奶奶酪酪的的相相對(duì)對(duì)價(jià)價(jià)格格大大于于其其機(jī)機(jī)會(huì)會(huì)成成本本時(shí)時(shí)，，該該國(guó)國(guó)才才會(huì)會(huì)專專業(yè)業(yè)化化生生產(chǎn)產(chǎn)奶奶酪酪））Intheabsenceoftrade,bothgoodsareproduced,andthereforePC/PW=aLC/aLW.162-3TradeinaOne-FactorWorldAssumptionsofthemodel（模模型型假假設(shè)設(shè)））:1.Therearetwocountriesintheworld(HomeandForeign).2.Eachofthetwocountriesproducestwogoods(saywineandcheese).3.Laboristheonlyfactorofproduction(生產(chǎn)產(chǎn)要要素素).4.Thesupplyoflaborisfixedineachcountry.5.Theproductivityoflaborineachgoodisfixed.6.Laborisnotmobileacrossthetwocountries.7.Perfectcompetitionprevailsinallmarkets.8.Allvariableswithanasteriskre’’fertotheForeigncountry.17AbsoluteAdvantage(絕對(duì)對(duì)優(yōu)優(yōu)勢(shì)勢(shì))Acountryhasanabsoluteadvantageinaproductionofagoodifithasalowerunitlaborrequirementthantheforeigncountryinthisgood.即，，當(dāng)當(dāng)一一個(gè)個(gè)國(guó)國(guó)家家能能以以少少于于其其他他國(guó)國(guó)家家的的勞勞動(dòng)動(dòng)投投入入生生產(chǎn)產(chǎn)出出同同樣樣單單位位商商品品時(shí)時(shí)，，則則該該國(guó)國(guó)在在生生產(chǎn)產(chǎn)此此商商品品上上具具有有絕絕對(duì)對(duì)優(yōu)優(yōu)勢(shì)勢(shì)。。AssumethataLC<a*LCandaLW<a*LWThisassumptionimpliesthatHomehasanabsoluteadvantageintheproductionofbothgoods.AnotherwaytoseethisistonoticethatHomeismoreproductiveintheproductionofbothgoodsthanForeign.EvenifHomehasanabsoluteadvantageinbothgoods,beneficialtradeispossible.Thepatternoftradewillbedeterminedbytheconceptofcomparativeadvantage.18ComparativeAdvantage假設(shè)本國(guó)用酒酒衡量的奶酪酪的機(jī)會(huì)成本本小于外國(guó)（AssumethataLC/aLW<a*LC/a*LW）(2-2)ThisassumptionimpliesthattheopportunitycostofcheeseintermsofwineislowerinHomethanitisinForeign.HomehasacomparativeadvantageincheeseandwillexportittoForeigninexchangeforwine.19F*P*L*/a*LWL*/a*LC外國(guó)葡萄酒的產(chǎn)量Q*W,ingallons外國(guó)奶酪的產(chǎn)量,Q*C,

inpounds+1圖2-2:外國(guó)的生產(chǎn)只只要能性曲線線20DeterminingtheRelativePriceAfterTradeWhatdeterminestherelativeprice(e.g.,PC/PW)aftertrade?Toanswerthisquestionwehavetodefinetherelativesupplyandrelativedemandforcheeseintheworldasawhole.Therelativesupplyofcheeseequalsthetotalquantityofcheesesuppliedbybothcountriesateachgivenrelativepricedividedbythetotalquantityofwinesupplied,(QC+Q*C)/(QW+Q*W).Therelativedemandofcheeseintheworldisasimilarconcept.212RD'RD1Q'aLC/aLWa*LC/a*LWRSFigure2-3:WorldRelativeSupplyandDemandRelativepriceofcheese,PC/PWRelativequantityofcheese,QC+Q*C

QW+Q*WL/aLCL*/a*LW22TheGainsfromTradeIfcountriesspecializeaccordingtotheircomparativeadvantage,theyallgainfromthisspecializationandtrade.Wewilldemonstratethesegainsfromtradeintwoways.First,wecanthinkoftradeasanewwayofproducinggoodsandservices(thatis,anewtechnology).23Anotherwaytoseethegainsfromtradeistoconsiderhowtradeaffectstheconsumptionineachofthetwocountries.Theconsumptionpossibilityfrontierstatesthemaximumamountofconsumptionofagoodacountrycanobtainforanygivenamountoftheothercommodity.Intheabsenceoftrade,theconsumptionpossibilitycurveisthesameastheproductionpossibilitycurve.Tradeenlargestheconsumptionpossibilityforeachofthetwocountries.24Figure2-4:TradeExpandsConsumptionPossibilities消費(fèi)可能的擴(kuò)擴(kuò)張TFPT*P*F*(a)Home(b)ForeignQuantityofwine,QWQuantityofcheese,QCQuantityofwine,Q*WQuantityofcheese,Q*C25ANumericalExampleThefollowingtabledescribesthetechnologyofthetwocounties:Table2-2:UnitLaborRequirements26Thepreviousnumericalexampleimpliesthat:aLC/aLW=1/2<a*LC/a*LW=2Inworldequilibrium,therelativepriceofcheesemustliebetweenthesevalues.AssumethatPc/PW=1gallonofwineperpoundofcheese.Bothcountrieswillspecializeandgainfromthisspecialization.ConsiderHome,whichcantransformwinetocheesebyeitherproducingitinternallyorbyproducingcheeseandthentradingthecheeseforwine.27Homecanuseonehouroflabortoproduce1/aLW=1/2gallonofwineifitdoesnottrade.Alternatively,itcanuseonehouroflabortoproduce1/aLC=1poundofcheese,sellthisamounttoForeign,andobtain1gallonofwine.28Intheabsenceoftrade,Foreigncanuseoneunitoflabortoproduce1/a*LC=1/6poundofcheeseusingthedomestictechnology.CanitdobetterbyspecializinginwineandtradingwinewithHomeforcheese?Inthepresenceoftrade,Foreigncanuseoneunitoflabortoproduce1/a*LW=1/3gallonofwine.SincetheworldpriceofwineisPW/PC=1poundofcheesepergallon,Foreigncanobtain1/3lbofcheesewhichismorethan1/6lb.29’RelativeWages(相對(duì)工資)Becausetherearetechnologicaldifferencesbetweenthetwocountries,tradeingoodsdoesnotmakethewagesequalacrossthetwocountries.Acountrywithabsoluteadvantageinbothgoodswillenjoyahigherwageaftertrade.30Thiscanbeillustratedwiththehelpofanumericalexample:AssumethatPC=$12andthatPW=$12.Therefore,wehavePC/PW=1asinourpreviousexample.SinceHomespecializesincheeseaftertrade,itswagewillbe(1/aLC)PC=(1/1)$12=$12.SinceForeignspecializesinwineaftertrade,itswagewillbe(1/a*LW)PW=(1/3)$12=$4.ThereforetherelativewageofHomewillbe$12/$4=3.Thus,thecountrywiththehigherabsoluteadvantagewillenjoyahigherwageaftertrade.31ProductivityandCompetitionMyth1:Freetradeisbeneficialonlyifacountryisstrongenoughtowithstandforeigncompetition.Thisargumentfailstorecognizethattradeisbasedoncomparativenotabsoluteadvantage.ThePauperLaborArgumentMyth2:Foreigncompetitionisunfairandhurtsothercountrieswhenitisbasedonlowwages.AgaininourexampleForeignhaslowerwagesbutstillbenefitsfromtrade.2-4MisconceptionsAboutComparativeAdvantage32ExploitationMyth3:Trademakestheworkersworseoffincountrieswithlowerwages.Intheabsenceoftradetheseworkerswouldbeworseoff.Denyingtheopportunitytoexportistocondemnpoorpeopletocontinuetobepoor.33Table2-3:ChangesinWagesandUnitLaborCosts34模型建立（（SettingUptheModel）Bothcountriesconsumeandareabletoproducealargenumber,N,ofdifferentgoods.按兩國(guó)生產(chǎn)產(chǎn)產(chǎn)品的相相對(duì)勞動(dòng)投投入排序：：a*L1/aL1＜a*L2/aL2＜a*L3/aL3＜…＜a*LN/aLN相對(duì)工資與與專業(yè)化（（RelativeWagesandSpecialization）貿(mào)易模式依依賴于兩國(guó)國(guó)的勞動(dòng)工工資（ThepatternoftradewilldependontheratioofHometoForeignwages.）成本最低原原則選擇產(chǎn)產(chǎn)品進(jìn)行專專業(yè)化生產(chǎn)產(chǎn)Goodswillalwaysbeproducedwhereitischeapesttomakethem.Forexample,itwillbecheapertoproducegoodiinHomeifwaLi<w*a*Lia*Li/aLi>w/w*.2-5ComparativeAdvantagewithManyGoods多產(chǎn)產(chǎn)品品模模型型中中的的比比較較優(yōu)優(yōu)勢(shì)勢(shì)35Table2-4:HomeandForeignUnitLaborRequirements36哪個(gè)個(gè)國(guó)國(guó)家家生生產(chǎn)產(chǎn)哪哪些些產(chǎn)產(chǎn)品品Whichcountryproduceswhichgoods?Acountryhasacostadvantageinanygoodforwhichitsrelativeproductivityishigherthanitsrelativewage.（取取決決于于相相對(duì)對(duì)工工資資率率和和相相對(duì)對(duì)生生產(chǎn)產(chǎn)效效率率））If,forexample,w/w*=3,Homewillproduceapples,bananas,andcaviar,whileForeignwillproduceonlydatesandenchiladas.Bothcountrieswillgainfromthisspecialization.37DeterminingtheRelativeWageintheMultigoodModel（多多產(chǎn)產(chǎn)品品模模型型中中相相對(duì)對(duì)工工資資的的決決定定））Todeterminerelativewagesinamultigoodeconomywemustlookbehindtherelativedemandforgoods(i.e.,therelativederiveddemand).（通通過(guò)過(guò)相相對(duì)對(duì)勞勞動(dòng)動(dòng)需需求求與與供供給給來(lái)來(lái)決決定定－－對(duì)對(duì)勞勞動(dòng)動(dòng)力力的的相相對(duì)對(duì)需需求求是是根根據(jù)據(jù)對(duì)對(duì)能能生生產(chǎn)產(chǎn)產(chǎn)產(chǎn)品品推推算算出出來(lái)來(lái)的的派派生生需需求求））TherelativedemandforHomelabordependsnegativelyontheratioofHometoForeignwages.（當(dāng)當(dāng)本本國(guó)國(guó)對(duì)對(duì)外外國(guó)國(guó)的的相相對(duì)對(duì)工工資資率率上上升升時(shí)時(shí)，，對(duì)對(duì)本本國(guó)國(guó)勞勞動(dòng)動(dòng)的的相相對(duì)對(duì)派派生生需需求求將將減減少少。。兩兩個(gè)個(gè)原原因因：：一一是是本本國(guó)國(guó)生生產(chǎn)產(chǎn)產(chǎn)產(chǎn)品品價(jià)價(jià)格格更更高高，，二二是是本本國(guó)國(guó)能能生生產(chǎn)產(chǎn)的的產(chǎn)產(chǎn)品品種種類類減減少少））38310Apples8Bananas4Caviar2Dates0.75EnchiladasRDFigure2-5:DeterminationofRelativeWagesRSRelativewageRate,w/w*Relativequantityoflabor,L/L*392-6運(yùn)輸輸費(fèi)費(fèi)用用和和非非貿(mào)貿(mào)易易品品AddingTransportCostsandNontradedGoods國(guó)際際經(jīng)經(jīng)濟(jì)濟(jì)中中，，專專業(yè)業(yè)分分工工不不是是極極端端的的原原因因有有三三個(gè)個(gè)（（Therearethreemainreasonswhyspecializationinther