比較優(yōu)勢理論(中英版)課件

Part1INTERNATIONALTRADETHEORYPart1INTERNATIONALTRADETHEOBasicAnalyticalToolsGeneralEquilibriumAnalysis一般均衡法GEAmeansanalyzingtwoormorethantworelatedmarketsatthesametime(eg.ExportMarketandImportMarket,GoodsMarketandFactorMarket)WeusuallyusethePPFandCICasthebasictoolsinthegeneralequilibriumanalysisofinternationaltrade.PartialEquilibriumAnalysis局部均衡法PEAmeansonlyanalyzingsinglemarketinonetimeWeusuallyusetheDemandCurveandtheSupplyCurveasthebasictoolsinthepartialequilibriumanalysis.BasicAnalyticalToolsGeneralGeneralEquilibriumAnalysisSupplySide:ProductionPossibilityFrontier(PPF)生產(chǎn)可能性曲線國際貿(mào)易實際上是國際市場上的供給（出口）與需求（進口）問題。為了研究一國能夠出口什么，需要進口什么，我們必須先研究一國的生產(chǎn)能力。在經(jīng)濟學(xué)中，為了表現(xiàn)整個國家的能生產(chǎn)什么，我們常常使用一種稱為“生產(chǎn)可能性曲線”的圖形。DemandSide:CommunityIndifferenceCurves(CIC)社會無差異曲線雖然在一個國家或經(jīng)濟社會里，每個人都有自己的消費偏好，很難找到一組能反映每一個消費者滿足程度的無差異曲線，但我們?nèi)匀荒苡靡环从称骄M效用的或反映大多數(shù)人消費偏好的無差異曲線圖來分析，我們稱之為“社會無差異曲線”。社會無差異曲線反映一國的平均消費偏好。GeneralEquilibriumAnalysisSu

ProductionPossibilityFrontierConception:PPF:Pointsdescribingalternativecombinationsofoutputlevels（生產(chǎn)組合）

fortwodifferentproductstobeproducedbygivenresources（既定的資源條件）生產(chǎn)可能性曲線（ProductionPossibilityFrontier,簡稱PPF）表明一個國家在充分和有效地使用其所有資源時能生產(chǎn)的各種商品數(shù)量的組合。QRQwPPFABCDETheshapeofPPFisdecidedbytheopportunityofcostofgoods。ProductionPossibilityFrontiOpportunityCostandPPFOpportunityCost(機會成本)Thecostofanactivityintermsofsacrificednextbestalternativeusesoftheassetsinvolved.Canalsobeformulatedas“amountofproduct2wemustgiveuptoproduceaunitofproduct1”.（生產(chǎn)一單位商品1所必須放棄的生產(chǎn)商品2的數(shù)量）OpportunityCostandPPFOpportOpportunityCostandPPF假設(shè)有大米（Rice）和小麥（Wheat）兩種商品。那么，大米的“機會成本”就是為了多生產(chǎn)一單位大米而必須放棄小麥的數(shù)量（QW/QR）。從幾何概念講，這也是PPF的斜率。PPFQRQwBCQRQwOpportunityCostandPPF假設(shè)有大米（QCConstantCostsQCDecreasingCostsQCIncreasingCostsQCQwPPFQCQwPPFQwQCPPF機會成本可以是不變的、遞增的或遞減的。相應(yīng)地，生產(chǎn)可能性曲線也就出現(xiàn)了直線的、外凸的或里凹的不同形狀.QCConstantCostsQCDecreasingCCommunityIndifferenceCurve

（社會無差異曲線）HigherSatisfactionthepointsdescribingsamelevelofsatisfaction(orutility)bygivenresource.CommunityIndifferenceCurve

（GEunderAutarky

(PPFwithconstantopportunitycosts)PPFQRQWQR1QW1GEunderAutarky

(PPFwithconPartialEquilibriumAnalysis在局部均衡分析中，我們只分析某個具體的商品市場或要素市場的情況，如中國的大米市場或中國的小麥?zhǔn)袌?，而不是同時分析這兩個市場。PartialEquilibriumunderautarkyPartialEquilibriumunderopeneconomyPartialEquilibriumAnalysis在局PartialEquilibriumunderautarkyQRPR/PW0SD231shortsurplusPartialEquilibriumunderautaCommoditymarketsinanOpen

Economy3X2MQRPRDSUSQRPRWorldMarketQRPRDSChina32CommoditymarketsinanOpen

E在本書的“國際貿(mào)易理論”中，我們主要運用一般均衡的分析方法來分析貿(mào)易利得，表現(xiàn)為貿(mào)易前后社會無差異曲線水平的變化；

在本書的“國際貿(mào)易政策”中，我們將運用局部均衡的方法來分析貿(mào)易利得，表現(xiàn)為消費者剩余、生產(chǎn)者剩余和凈福利的增減。在本書的“國際貿(mào)易理論”中，我們主要運用一般均衡的分析方法來

ComparativeAdvantageModelCHAPTER2

ComparativeAdvantageModelCHLimitationoftheSmith’sModelHomeForeignLabor100100GoodsCloth10080Wheat50100Produc-tivityClothWheatInthiscase,Foreignhastheabsoluteadvantageinbothgoods(itisverycommonforadevelopedcountrytohaveabsoluteadvantagesinmostsectors).AccordingtotheSmiththeory,therewillbenotrade.(Really?)15010.51.51LimitationoftheSmith’sModeComparativeAdvantageTheoryDavidRicardoComparativeAdvantageRicardo’sModelDiscussion1:MisconceptionsaboutComparativeAdvantageComparativeAdvantageTheoryDaDavidRicardo(1772-1823)HewasborninLondonandwasthethirdof17children.hadlittleformaleducationandwenttoworkforhisfatherattheageof14,successfully.attheageof27,turnedhisattentiontoeconomic.Oneofthegreatestpoliticaleconomists.DavidRicardo(1772-1823)Hewas“PrinciplesofPoliticalEconomy,andTaxation”“PrinciplesofPoliticalEco自由貿(mào)易政策的初次嘗試從亞當(dāng)·斯密以后的短時期間，英國人口的實際增長使谷物需求超過了供給，使一蒲式耳小麥的價格漲了三倍。于是有膽量的商人進口國外的小麥和燕麥。海外來的廉價谷物泛濫市場是地主們所難以忍受的。他們控制議會通過了“谷物法”，對谷物的進口規(guī)定了一個有伸縮性的稅收制度，國外價格越低，則征稅越高。谷物價格飛漲！一蒲式耳小麥的售價等于一個工人的每周全部工資的兩倍。自由貿(mào)易政策的初次嘗試從亞當(dāng)·斯密以后的短時期間，英國人口的李嘉圖認為：谷物價格上升會使地主地租收入上升，農(nóng)業(yè)工人收入上升，同時生活費用上升，工廠工人工資上升，資本家的利潤下降，導(dǎo)致資本積累減少。所以李嘉圖認為必須廢除《谷物法》實行自由貿(mào)易。出口工業(yè)制成品，進口國外價格低廉的生活必需品，提高國內(nèi)生活必需品的供給，使工資水平下降，利潤水平提高，積累增加，社會財富增加。1846年，英國議會通過廢除《谷物法》的法令。李嘉圖認為：22$25$25$30$22$25$25$30$FamilyIncome5*25=1255*30=1505*22=1105*25=1255100*25=010*30=30010*22=2200*25=052010*25=2500*30=00*22=010*25=250500FamilyIncome5*25=1255*30=1505BestCooperationinFamilySo,thebestdivisionoflaborinonefamilyisthatwomendoinghouseworkandmengoingoutforwork.“兩利相權(quán)取其重，兩弊相權(quán)取其輕。”Womenhavecomparativeadvantageinhousework,andmenhavecomparativeadvantageinout-house-work.BestCooperationinFamilySo,Ricardo’sModelBasicAssumptionsPPFOpportunityCostRelativePriceDifferenceinrelativepriceInternationalTradeundercomparativeadvantageGainfromTradeRicardo’sModelBasicAssumptioBasicAssumptionsOneinput(單一要素):Labor(L)Twooutputs:Wine(Qw)andCheese(Qc)Twocountries:

HomeandForeign(*)Costsareconstantandtherearenoeconomiesofscale.

Factorsofproductionareperfectlymobile（生產(chǎn)要素完全流動）.Otherassumptions:Goodsareidentical（產(chǎn)品同質(zhì)）.Perfectknowledge（信息完全）.Notransportcosts（沒有運輸成本）.Notariffsorothertradebarriers（沒有貿(mào)易壁壘）.BasicAssumptionsOneinput(單一要QCQWHome’sPPF:aLCQC+aLwQw≤L當(dāng)本國完全生產(chǎn)奶酪時，QC=L/aLC當(dāng)本國完全生產(chǎn)葡萄酒時，QW=L/aLWL/aLW·L/aLC·SlopofPPF(斜率)：aLC/aLW生產(chǎn)一單位奶酪的機會成本是：QW/QC=aLC/aLW=QCQWHome’sPPF:aLCQC+aLwQw≤Foreign’sPPF:a*LCQ*C+a*LwQ*w≤L*Q*CQ*WL*/a*LW·L*/a*LC·SlopofPPF*(斜率)：a*LC/a*LW

當(dāng)外國完全生產(chǎn)奶酪時，Q*C=L*/a*LC當(dāng)外國完全生產(chǎn)葡萄酒時，Q*W=L*/a*LW外國生產(chǎn)一單位奶酪的機會成本是：Q*W/Q*C=a*LC/a*LW=Foreign’sPPF:a*LCQ*C+a*LwQ*opportunitycost&relativepriceIntheautarky,bothcountrieshavetoproducebothgoodsforthemselves.Letsconsiderthewageoflaborinbothsector：

WC=PCMPLC;WW=PWMPLW→WC=PC/

aLC;WW=PW/aLWTheremustbeWC=WW,becauselaborareperfectlymobileSo,PC/

aLC=PW/aLW→PC/PW=aLC/aLW

opportunitycost&relativeprPC/PW=aLC/aLWInacompetitiveeconomy,onlywhentherelativepriceofgoods（PC/PW）

equaltotheopportunitycostofgoods（aLC/

aLw）,willthelaborsproducebothgoods.在一個自由競爭的封閉社會，只有當(dāng)兩種商品的相對價格等于它們的機會成本時，勞動者才會同時生產(chǎn)這兩種商品。PC/PW=aLC/aLWInacompetitiRelativePriceDifference

(相對價格差)本國奶酪的相對價格PC/PW

＝aLC/

aLw外國奶酪的相對價格P*C/P*W

＝a*LC/

a*LwIfthereisrelativepricedifferencebetweentheHomeandtheForeign,internationaltrademayhappen.如果本國奶酪的相對價格＜外國奶酪的相對價格aLC/

aLw

＜a*LC/

a*LwHomewillhasthecomparativeadvantageinCheeseRelativePriceDifference

(相對價aLC/

aLw

＜

a*LC/

a*LwQCQWL/aLW·L/aLC·Slop：aLC/aLWHomeQ*CQ*WL*/a*LW·L*/a*LC·Slop：a*LC/a*LW

Foreign從圖形上直觀地看，當(dāng)本國PPF斜率小于外國PPF斜率（較平坦）時，本國在奶酪上有比較優(yōu)勢aLC/aLw＜a*LC/a*LwQCQWL/aLW2004我國農(nóng)產(chǎn)品貿(mào)易首現(xiàn)貿(mào)逆差據(jù)海關(guān)統(tǒng)計分析，我國農(nóng)產(chǎn)品進口增幅大大超過出口增幅，農(nóng)產(chǎn)品貿(mào)易由2003年同期順差19.4億美元轉(zhuǎn)變?yōu)槟娌?5億美元。2004我國農(nóng)產(chǎn)品貿(mào)易首現(xiàn)貿(mào)逆差據(jù)海關(guān)統(tǒng)計分析，我國農(nóng)產(chǎn)品進從海關(guān)統(tǒng)計數(shù)據(jù)來看，高額逆差的產(chǎn)生主要緣自三大農(nóng)產(chǎn)品進口數(shù)量的增加：一是谷物類，二是作為工業(yè)原料的棉花和糖，三是近年來出口快速增長的畜禽產(chǎn)品。從海關(guān)統(tǒng)計數(shù)據(jù)來看，高額逆差的產(chǎn)生主要緣自三大農(nóng)產(chǎn)品進口數(shù)量AccordingtoRicardo’sRule,eachcountryshouldspecializeinandexporttheproductinwhichithasacomparativeadvantage

(各個國家應(yīng)專業(yè)生產(chǎn)并出口那些他們具有比較優(yōu)勢的產(chǎn)品）Inthiscase,HomeshouldbespecializedinproductionofcheeseandForeignshouldproducewine.InternationalTradeunderthecomparativeadvantageAccordingtoRicardo’sRule,eDeterminingtheRelativePriceafterTrade奶酪的世界相對價格，(PC/PW)w奶酪的相對產(chǎn)量，QC/QC+WaLC/aLWa*LC/a*LW1.SupplySide(RelativeSupply):1).(PC/PW)w

＜

aLC/aLW,nocountrieswanttoproducecheese2).(PC/PW)w

＝

aLC/aLW,Homeindifferencetobothgoods·3).aLC/aLW＜

(PC/PW)w

＜

a*LC/a*LW,Homespecializedincheese,andForeignspecializedinwine4).(PC/PW)w

=aLC/aLW,Foreignindifferencetobothgoods5).(PC/PW)w

＞

a*LC/a*LW,bothcountriesspecializedincheeseRSRDRD’DeterminingtheRelativePriceSpecializations&Trade

(專業(yè)化生產(chǎn)與國際貿(mào)易)Thenormalresultoftradeisthattherelativepriceofatradedgoodsendedupsomewhereinbetweenitspretradelevelsinthetwocountries.aLC/

aLw＜(PC/PW)w＜a*LC/

a*LwSpecializations&Trade

(專業(yè)化生產(chǎn)Willthetrademutualbeneficial?Themutualgaincanbedemonstratedintwoways(兩種方法可以證明):1)thinkoftradeasanindirectmethodofproduction:Now,thereis1hourlabor,Homecanproduce1/aLwwine,orHomecanproduce1/aLCcheeseandexportitforwine,

(1/aLC)×(PC/PW)w

＞

(1/aLC)×PC/PW=(1/aLC)×aLC/

aLw

=1/aLwThatshowsthatHomecan“produce”winemoreefficientlybymakingcheeseandtradingit.WillthetrademutualbeneficiWillthetrademutualbeneficial?2)toexaminehowtradeaffectseachcountry’spossibilitiesforconsumption:QCQWL/aLW·L/aLC·Pretrade:aLC/aLWHome·貿(mào)易后的專業(yè)化生產(chǎn)點貿(mào)易后相對價格線貿(mào)易擴大了各國消費選擇的范圍，因此提高了各國居民的福利水平。WillthetrademutualbeneficiExampleWhichcountryhasthecomparativeadvantageincloth?Andwhichcountryhasthecomparativeadvantageinwheat?Pleaseshowtheeffectsoftradeaccordingtothecomparativeadvantagetheory.HomeForeignLabor100100GoodsCloth10080Wheat50100150ExampleWhichcountryhasthecFirstStep:PPF→RelativePriceHomeForeignQcQW05010050PPFPC/PW=0.5PPFP*C/P*W=0.67QRQW05010050100150FirstStep:PPF→RelativePriceHSecondStep:

ComparativeAdvantage

→TradePatternBecause0.5=PC/PW＜

P*C/P*W=0.67Homehasadvantageincloth;Foreignhasadvantageinwheat.So,Homeshouldspecializeinandexportcloth,andForeignshouldspecializeinandexportwheat.PC/PW＜

(PC/PW)w＜

P*C/P*WSecondStep:

ComparativeAdvanThirdStep:gainfromtrade1)thinkoftradeasanindirectmethodofproduction:Inautarky,Homecanuse100laborproduce50wheat;Now,homespecializeinproducing100cloth;Assume(PC/PW)W=0.6,100clothcanbeexchangeto60wheat,whichmorethanproducingbyitself.ThirdStep:gainfromtrade1)thThirdStep:gainfromtrade2)toexaminehowtradeaffectseachcountry’spossibilitiesforconsumption:PC/PW=0.5HomeQcQW0501005060(PC/PW)w=0.6社會無差異曲線的右移代表社會滿足程度（福利的提高）ThirdStep:gainfromtrade2)toDiscussion1：

MisconceptionsaboutCAProductivityandCompetitiveness(勞動生產(chǎn)率和競爭力）ThePauperLaborArgument（貧民勞動論）Exploitation（剝削）Discussion1：

MisconceptionsaEvaluationAlfredMarshall,1842-1924“Thatdoctrine...establishedbyRicardo...Idonotknowthatanypersonhasshakenitintheleast,infact,Idonotmyselfbelievethatithaseverbeenseriouslyattackedbyanyonewhohastakenthetroubletounderstandit”EvaluationAlfredMarshall,184Part1INTERNATIONALTRADETHEORYPart1INTERNATIONALTRADETHEOBasicAnalyticalToolsGeneralEquilibriumAnalysis一般均衡法GEAmeansanalyzingtwoormorethantworelatedmarketsatthesametime(eg.ExportMarketandImportMarket,GoodsMarketandFactorMarket)WeusuallyusethePPFandCICasthebasictoolsinthegeneralequilibriumanalysisofinternationaltrade.PartialEquilibriumAnalysis局部均衡法PEAmeansonlyanalyzingsinglemarketinonetimeWeusuallyusetheDemandCurveandtheSupplyCurveasthebasictoolsinthepartialequilibriumanalysis.BasicAnalyticalToolsGeneralGeneralEquilibriumAnalysisSupplySide:ProductionPossibilityFrontier(PPF)生產(chǎn)可能性曲線國際貿(mào)易實際上是國際市場上的供給（出口）與需求（進口）問題。為了研究一國能夠出口什么，需要進口什么，我們必須先研究一國的生產(chǎn)能力。在經(jīng)濟學(xué)中，為了表現(xiàn)整個國家的能生產(chǎn)什么，我們常常使用一種稱為“生產(chǎn)可能性曲線”的圖形。DemandSide:CommunityIndifferenceCurves(CIC)社會無差異曲線雖然在一個國家或經(jīng)濟社會里，每個人都有自己的消費偏好，很難找到一組能反映每一個消費者滿足程度的無差異曲線，但我們?nèi)匀荒苡靡环从称骄M效用的或反映大多數(shù)人消費偏好的無差異曲線圖來分析，我們稱之為“社會無差異曲線”。社會無差異曲線反映一國的平均消費偏好。GeneralEquilibriumAnalysisSu

ProductionPossibilityFrontierConception:PPF:Pointsdescribingalternativecombinationsofoutputlevels（生產(chǎn)組合）

fortwodifferentproductstobeproducedbygivenresources（既定的資源條件）生產(chǎn)可能性曲線（ProductionPossibilityFrontier,簡稱PPF）表明一個國家在充分和有效地使用其所有資源時能生產(chǎn)的各種商品數(shù)量的組合。QRQwPPFABCDETheshapeofPPFisdecidedbytheopportunityofcostofgoods。ProductionPossibilityFrontiOpportunityCostandPPFOpportunityCost(機會成本)Thecostofanactivityintermsofsacrificednextbestalternativeusesoftheassetsinvolved.Canalsobeformulatedas“amountofproduct2wemustgiveuptoproduceaunitofproduct1”.（生產(chǎn)一單位商品1所必須放棄的生產(chǎn)商品2的數(shù)量）OpportunityCostandPPFOpportOpportunityCostandPPF假設(shè)有大米（Rice）和小麥（Wheat）兩種商品。那么，大米的“機會成本”就是為了多生產(chǎn)一單位大米而必須放棄小麥的數(shù)量（QW/QR）。從幾何概念講，這也是PPF的斜率。PPFQRQwBCQRQwOpportunityCostandPPF假設(shè)有大米（QCConstantCostsQCDecreasingCostsQCIncreasingCostsQCQwPPFQCQwPPFQwQCPPF機會成本可以是不變的、遞增的或遞減的。相應(yīng)地，生產(chǎn)可能性曲線也就出現(xiàn)了直線的、外凸的或里凹的不同形狀.QCConstantCostsQCDecreasingCCommunityIndifferenceCurve

（社會無差異曲線）HigherSatisfactionthepointsdescribingsamelevelofsatisfaction(orutility)bygivenresource.CommunityIndifferenceCurve

（GEunderAutarky

(PPFwithconstantopportunitycosts)PPFQRQWQR1QW1GEunderAutarky

(PPFwithconPartialEquilibriumAnalysis在局部均衡分析中，我們只分析某個具體的商品市場或要素市場的情況，如中國的大米市場或中國的小麥?zhǔn)袌?，而不是同時分析這兩個市場。PartialEquilibriumunderautarkyPartialEquilibriumunderopeneconomyPartialEquilibriumAnalysis在局PartialEquilibriumunderautarkyQRPR/PW0SD231shortsurplusPartialEquilibriumunderautaCommoditymarketsinanOpen

Economy3X2MQRPRDSUSQRPRWorldMarketQRPRDSChina32CommoditymarketsinanOpen

E在本書的“國際貿(mào)易理論”中，我們主要運用一般均衡的分析方法來分析貿(mào)易利得，表現(xiàn)為貿(mào)易前后社會無差異曲線水平的變化；

在本書的“國際貿(mào)易政策”中，我們將運用局部均衡的方法來分析貿(mào)易利得，表現(xiàn)為消費者剩余、生產(chǎn)者剩余和凈福利的增減。在本書的“國際貿(mào)易理論”中，我們主要運用一般均衡的分析方法來

ComparativeAdvantageModelCHAPTER2

ComparativeAdvantageModelCHLimitationoftheSmith’sModelHomeForeignLabor100100GoodsCloth10080Wheat50100Produc-tivityClothWheatInthiscase,Foreignhastheabsoluteadvantageinbothgoods(itisverycommonforadevelopedcountrytohaveabsoluteadvantagesinmostsectors).AccordingtotheSmiththeory,therewillbenotrade.(Really?)15010.51.51LimitationoftheSmith’sModeComparativeAdvantageTheoryDavidRicardoComparativeAdvantageRicardo’sModelDiscussion1:MisconceptionsaboutComparativeAdvantageComparativeAdvantageTheoryDaDavidRicardo(1772-1823)HewasborninLondonandwasthethirdof17children.hadlittleformaleducationandwenttoworkforhisfatherattheageof14,successfully.attheageof27,turnedhisattentiontoeconomic.Oneofthegreatestpoliticaleconomists.DavidRicardo(1772-1823)Hewas“PrinciplesofPoliticalEconomy,andTaxation”“PrinciplesofPoliticalEco自由貿(mào)易政策的初次嘗試從亞當(dāng)·斯密以后的短時期間，英國人口的實際增長使谷物需求超過了供給，使一蒲式耳小麥的價格漲了三倍。于是有膽量的商人進口國外的小麥和燕麥。海外來的廉價谷物泛濫市場是地主們所難以忍受的。他們控制議會通過了“谷物法”，對谷物的進口規(guī)定了一個有伸縮性的稅收制度，國外價格越低，則征稅越高。谷物價格飛漲！一蒲式耳小麥的售價等于一個工人的每周全部工資的兩倍。自由貿(mào)易政策的初次嘗試從亞當(dāng)·斯密以后的短時期間，英國人口的李嘉圖認為：谷物價格上升會使地主地租收入上升，農(nóng)業(yè)工人收入上升，同時生活費用上升，工廠工人工資上升，資本家的利潤下降，導(dǎo)致資本積累減少。所以李嘉圖認為必須廢除《谷物法》實行自由貿(mào)易。出口工業(yè)制成品，進口國外價格低廉的生活必需品，提高國內(nèi)生活必需品的供給，使工資水平下降，利潤水平提高，積累增加，社會財富增加。1846年，英國議會通過廢除《谷物法》的法令。李嘉圖認為：22$25$25$30$22$25$25$30$FamilyIncome5*25=1255*30=1505*22=1105*25=1255100*25=010*30=30010*22=2200*25=052010*25=2500*30=00*22=010*25=250500FamilyIncome5*25=1255*30=1505BestCooperationinFamilySo,thebestdivisionoflaborinonefamilyisthatwomendoinghouseworkandmengoingoutforwork.“兩利相權(quán)取其重，兩弊相權(quán)取其輕。”Womenhavecomparativeadvantageinhousework,andmenhavecomparativeadvantageinout-house-work.BestCooperationinFamilySo,Ricardo’sModelBasicAssumptionsPPFOpportunityCostRelativePriceDifferenceinrelativepriceInternationalTradeundercomparativeadvantageGainfromTradeRicardo’sModelBasicAssumptioBasicAssumptionsOneinput(單一要素):Labor(L)Twooutputs:Wine(Qw)andCheese(Qc)Twocountries:

HomeandForeign(*)Costsareconstantandtherearenoeconomiesofscale.

Factorsofproductionareperfectlymobile（生產(chǎn)要素完全流動）.Otherassumptions:Goodsareidentical（產(chǎn)品同質(zhì)）.Perfectknowledge（信息完全）.Notransportcosts（沒有運輸成本）.Notariffsorothertradebarriers（沒有貿(mào)易壁壘）.BasicAssumptionsOneinput(單一要QCQWHome’sPPF:aLCQC+aLwQw≤L當(dāng)本國完全生產(chǎn)奶酪時，QC=L/aLC當(dāng)本國完全生產(chǎn)葡萄酒時，QW=L/aLWL/aLW·L/aLC·SlopofPPF(斜率)：aLC/aLW生產(chǎn)一單位奶酪的機會成本是：QW/QC=aLC/aLW=QCQWHome’sPPF:aLCQC+aLwQw≤Foreign’sPPF:a*LCQ*C+a*LwQ*w≤L*Q*CQ*WL*/a*LW·L*/a*LC·SlopofPPF*(斜率)：a*LC/a*LW

當(dāng)外國完全生產(chǎn)奶酪時，Q*C=L*/a*LC當(dāng)外國完全生產(chǎn)葡萄酒時，Q*W=L*/a*LW外國生產(chǎn)一單位奶酪的機會成本是：Q*W/Q*C=a*LC/a*LW=Foreign’sPPF:a*LCQ*C+a*LwQ*opportunitycost&relativepriceIntheautarky,bothcountrieshavetoproducebothgoodsforthemselves.Letsconsiderthewageoflaborinbothsector：

WC=PCMPLC;WW=PWMPLW→WC=PC/

aLC;WW=PW/aLWTheremustbeWC=WW,becauselaborareperfectlymobileSo,PC/

aLC=PW/aLW→PC/PW=aLC/aLW

opportunitycost&relativeprPC/PW=aLC/aLWInacompetitiveeconomy,onlywhentherelativepriceofgoods（PC/PW）

equaltotheopportunitycostofgoods（aLC/

aLw）,willthelaborsproducebothgoods.在一個自由競爭的封閉社會，只有當(dāng)兩種商品的相對價格等于它們的機會成本時，勞動者才會同時生產(chǎn)這兩種商品。PC/PW=aLC/aLWInacompetitiRelativePriceDifference

(相對價格差)本國奶酪的相對價格PC/PW

＝aLC/

aLw外國奶酪的相對價格P*C/P*W

＝a*LC/

a*LwIfthereisrelativepricedifferencebetweentheHomeandtheForeign,internationaltrademayhappen.如果本國奶酪的相對價格＜外國奶酪的相對價格aLC/

aLw

＜a*LC/

a*LwHomewillhasthecomparativeadvantageinCheeseRelativePriceDifference

(相對價aLC/

aLw

＜

a*LC/

a*LwQCQWL/aLW·L/aLC·Slop：aLC/aLWHomeQ*CQ*WL*/a*LW·L*/a*LC·Slop：a*LC/a*LW

Foreign從圖形上直觀地看，當(dāng)本國PPF斜率小于外國PPF斜率（較平坦）時，本國在奶酪上有比較優(yōu)勢aLC/aLw＜a*LC/a*LwQCQWL/aLW2004我國農(nóng)產(chǎn)品貿(mào)易首現(xiàn)貿(mào)逆差據(jù)海關(guān)統(tǒng)計分析，我國農(nóng)產(chǎn)品進口增幅大大超過出口增幅，農(nóng)產(chǎn)品貿(mào)易由2003年同期順差19.4億美元轉(zhuǎn)變?yōu)槟娌?5億美元。2004我國農(nóng)產(chǎn)品貿(mào)易首現(xiàn)貿(mào)逆差據(jù)海關(guān)統(tǒng)計分析，我國農(nóng)產(chǎn)品進從海關(guān)統(tǒng)計數(shù)據(jù)來看，高額逆差的產(chǎn)生主要緣自三大農(nóng)產(chǎn)品進口數(shù)量的增加：一是谷物類，二是作為工業(yè)原料的棉花和糖，三是近年來出口快速增長的畜禽產(chǎn)品。從海關(guān)統(tǒng)計數(shù)據(jù)來看，高額逆差的產(chǎn)生主要緣自三大農(nóng)產(chǎn)品進口數(shù)量AccordingtoRicardo’sRule,eachcountryshouldspecializeinandexporttheproductinwhichithasacomparativeadvantage

(各個國家應(yīng)專業(yè)生產(chǎn)并出口那些他們具有比較優(yōu)勢的產(chǎn)品）Inthiscase,HomeshouldbespecializedinproductionofcheeseandForeignshouldproducewine.InternationalTradeunderthecomparativeadvantageAccordingtoRicardo’sRule,eDeterminingtheRelativePriceafterTrade奶酪的世界相對價格，(PC/PW)w奶酪的相對產(chǎn)量，QC/QC+WaLC/aLWa*LC/a*LW1.SupplySide(RelativeSupply):1).(PC/PW)w

＜

aLC/aLW,nocountrieswanttoproducecheese2).(PC/PW)w

＝

aLC/aLW,Homeindifferencetobothgoods·3).aLC/aLW＜

(PC/PW)w

＜

a*LC/a*LW,Homespecializedincheese,andForeignspecializedinwine4).(PC/PW)w

=aLC/aLW,Foreignindifferencetobothgoods5).(PC/PW)w

＞

a*LC/a*LW,bothcountriesspecializedincheeseRSRDRD’DeterminingtheRelativePriceSpecializations&Trade

(專業(yè)化生產(chǎn)與國際貿(mào)易)Thenormalresultoftradeisthattherelativepriceofatradedgoodsendedupsomewhereinbetweenitspretradelevelsinthetwocountries.aLC/

aLw＜(PC/PW)w＜a*LC/

a*LwSpecializations&Trade

(專業(yè)化生產(chǎn)Willthetrademutualbeneficial?Themutualgaincanbedemonstratedintwoways(兩種方法可以證明):1)thinkoftradeasanindirectmethodofproduction:Now,thereis1hourlabor,Homecanproduce1/aLwwine,orHomecanproduce1/aLCcheeseandexportitforwine,

(1/aLC)×(PC/PW)w

＞

(1/aLC