SlidespreparedbyThomasBishopCopyright©2009PearsonAddison-Wesley.Allrightsreserved.Chapter3LaborProductivity,ComparativeAdvantageandInternationalTrade:TheRicardianModel3-2Preview•TheMercantilists’ViewsonTrade•TradeBasedonAbsoluteAdvantage:AdamSmith•TradeBasedonComparativeAdvantage:DavidRicardo•Opportunitycostsandcomparativeadvantage•AOneFactorRicardianModel•Gainsfromtrade•EmpiricalevidenceonRicardianModelAGuidingCase•在每年情人节时,美国对玫瑰有很高的需求,但是在冬天美国种植玫瑰比较困难,一方面需要加热的温室,另一方面需要投入更多的劳动力和资本。相反,同样的时间,南美生产玫瑰的成本就很低,但是南美由于技术和资本的限制,生产计算机的成本却很高。假定美国生产100支玫瑰的资源可以生产10台计算机,南美生产100支玫瑰的资源可以生产3台计算机。通过简单计算就能发现,如果两个国家都专业化生产自己生产效率高的产品的话——美国生产计算机,南美生产玫瑰,并相互贸易,二者都可以在贸易中获利。3-4BasicQuestions•Whatisthebasisfortrade?•Whatisthepatternoftrade?•Whataregainsfromtrade?TheMercantilists’ViewsonTrade(重商主义的贸易思想)3-5Mercantilism(重商主义)•Economicphilosophyin15thand18thcenturies.•早期重商主义以“货币差额论”为中心,其代表人物是英国的威廉·斯塔福(WilliamStafford,1554-1612)。晚期重商主义以“贸易差额论”为中心,代表人物是英国的托马斯·孟(ThomasMun,1571-1641)。•Beliefthatnationcouldbecomerichandpowerfulonlybyexportingmorethanitimported.TheMercantilists’ViewsonTrade•Tradesurplusesbroughtinflowofgoldandsilver.•Tradepolicywastoencourageexportsandrestrictimports(贸易政策是奖出限入).•Onenationgainedonlyattheexpenseofanother(zero-sumgame,零和博弈).----Doyouagree?TheMercantilists’ViewsonTrade(cont.)•Mercantilistsmeasuredwealthofanationbystockofpreciousmetalsitpossessed.(重商主义这以一个国家拥有的贵金属作为衡量其财富的象征。)•Today,wemeasurewealthofanationbyitsstockofhuman,man-madeandnaturalresourcesavailableforproducinggoodsandservices.Thegreaterthestockofresources,thegreatertheflowofgoodsandservicestosatisfyhumanwants,andthehigherthestandardofliving.Discussion•HowtoevaluatetheMercantilism?•WhyChina’sgovernmentwerebeingboredwiththeincreasingtradesurplusinrecentyears?3-92005-2013中国的贸易顺差和外汇储备(单位:亿美元)200520062007200820092010201120122013贸易顺差102017752618298119571815155123112598外汇储备81891066315283194602399228473318113311638395TradeBasedonAbsoluteAdvantage(绝对优势):TheSmithModel3-10AbsoluteAdvantageandTrade•AdamSmith(亚当·斯密).InquiryintotheNatureandCausesofWealthofNations,1776.•Anationhasabsoluteadvantage(绝对优势)overanothernationifitcanproduceacommoditymoreefficiently.•Whenonenationhasabsoluteadvantageinproductionofacommodity,butanabsolutedisadvantagewithrespecttotheothernationinasecondcommodity,bothnationscangainbyspecializingintheirabsoluteadvantagegoodandexchangingpartoftheoutputforthecommodityofitsabsolutedisadvantage(绝对劣势).•亚当·斯密的自由贸易思想斯密主张自由贸易(交换),认为国际贸易是自由市场经济的一部分,不应加以任何限制。斯密认为,国际贸易和国际分工的原因及基础是各国间存在的劳动生产率和生产成本的绝对差别。各国应专业化生产并出口具有劳动生产率和生产成本“绝对优势”的产品,不生产并进口其不具有“绝对优势”的产品,其结果比自己什么都生产更有利。一个别针工厂的例子•亚当·斯密在工业革命的高潮中思考一个问题,为什么一些国家富有天下,一些国家却一贫如洗?他通过强调劳动分工与自由市场的作用来回答这个问题。他在《国富论》中举了一个别针工厂的例子,用18世纪70年代的手工工具,1个工人1天能造20个别针。而如果通过劳动分工,把整个生产过程分解为若干个工人专门从事的工序,第一个人负责拉铁丝,第二个人负责弄直,第三个人负责切断,第四个人负责削尖,第五个人负责磨光,然后有三个人做针帽,再有一个人负责固定,最后再将别针擦亮并包装。这样,即使同样的手工工具,1个工人一天可以惊人地完成4800个别针!•思考:如果没有很大的市场,这种劳动分工能否得到支撑?•绝对优势的衡量方法:(1)用劳动生产率(LaborProductivity),即用单位要素投入的产出率来衡量:(2)用生产成本(ProductionCost),即用生产一单位产品所需的要素投入数量来衡量:LQjjLjQLaAnExample•Canadaisefficientingrowingwheat,inefficientingrowingbananas.•Brazilisefficientingrowingbananas,inefficientingrowingwheat.•Canadahasabsoluteadvantageinwheat,Brazilhasabsoluteadvantageinbananas.•Mutuallybeneficialtradecantakeplaceifbothcountriesspecializeintheirabsoluteadvantage.AnExample(cont.)CanadaBrazilWheat(kg/laborhour)61Banana(kg/laborhour)35CanadahasabsoluteadvantageoverBrazilinwheat.BrazilhasabsoluteadvantageoverCanadainbanana.Canadacouldspecializeinproductionofwheat,Brazilcouldspecializeinproductionofbanana,andexchangepartoftheproductofitsabsoluteadvantage.Bothnationscangainfromspecializationinproductionandtrade.绝对优势理论的局限性:无法解释绝对先进和绝对落后国家之间的贸易发达国家和发展中国家的贸易为什么会发生?CanadaBrazilWheat(kg/laborhour)61Banana(kg/laborhour)42TradeBasedonComparativeAdvantage:TheRicardianModel3-18ComparativeAdvantage(比较优势)•DavidRicardo(大卫·李嘉图).OnthePrinciplesofPoliticalEconomyandTaxation,1979.•LawofComparativeAdvantageEvenifonenationislessefficientthan(hasabsolutedisadvantagewithrespectto)theothernationinproductionofbothcommodities,thereisstillabasisformutuallybeneficialtrade.Oftwoadvantageschoosethemore,whileoftwodisadvantageschoosetheless(两利相权取其重,两弊相权取其轻).ComparativeAdvantage:ANumericalExampleBrazilhasabsolutedisadvantageinbothgoods.SinceBrazillaborishalfasproductiveinBananabutsixtimeslessproductiveinwheatcomparedtoCanada,BrazilhasacomparativeadvantageinBanana.Canadahascomparativeadvantageinwheat.CanadaBrazilWheat(kg/laborhour)61Banana(kg/laborhour)42ComparativeAdvantageandOpportunityCosts•Theoriginalideaofcomparativeadvantagewasbasedonthelabortheoryofvalue:Thevalueorpriceofacommoditydependsexclusivelyontheamountoflaborusedtoproduceit.•Canusetheopportunitycost(机会成本)theorytoexplaincomparativeadvantage:Thecostofacommodityistheamountofasecondcommoditythatmustbegivenuptoreleasejustenoughresourcestoproduceoneadditionalunitofthefirstcommodity.3-22ComparativeAdvantageandOpportunityCost(cont.)•Acountryhasacomparativeadvantageinproducingagoodiftheopportunitycostofproducingthatgoodisloweri