1、lIntroductionlA Standard Model of a Trading EconomylInternational Transfers of Income:Shifting the RD CurvelTariffs and Export Subsidies:Simultaneous Shifts in RS and RDlSummarylAppendix:Representing International Equilibrium with Offer CurveslPrevious trade theories have emphasized specific sources
2、 of comparative advantage which give rise to international trade:Differences in labor productivity(Ricardian model)Differences in resources(specific factors model and Heckscher-Ohlin model)lThe standard trade model is a general model of trade that admits these models as special cases.lThe standard t
3、rade model is built on four key relationships:Production possibility frontier and the relative supply curveRelative prices and relative demandWorld relative supply and world relative demandTerms of trade and national welfarelProduction Possibilities and Relative SupplyAssumptions of the model:lEach
4、country produces two goods,food(F)and cloth(C)lEach countrys production possibility frontier is a smooth curve(TT)The point on its production possibility frontier at which an economy actually produces depends on the price of cloth relative to food,PC/PF.Isovalue lines(P94)lLines along which the mark
5、et value of output is constantFigure 5-1:Relative Prices Determine the Economys Output(P95)QIsovalue linesTT Cloth production,QCFood production,QFFigure 5-2:How an Increase in the Relative Price of Cloth Affects Relative Supply(P96)Q1VV1(PC/PF)1Q2VV2(PC/PF)2TT Cloth production,QCFood production,QFlR
6、elative Prices and DemandThe value of an economys consumption equals the value of its production:PCQC+PFQF=PCDC+PFDF=VThe economys choice of a point on the isovalue line depends on the tastes of its consumers,which can be represented graphically by a series of indifference curves.Indifference curves
7、(P96)lEach traces a set of combinations of two goods consumption that leave the individual equally well offlThey have three properties:Downward sloping The farther up and to the right each lies,the higher the level of welfare to which it corresponds Each gets flatter as we move to the rightTTFigure
8、5-3:Production,Consumption,and Trade in the Standard Model(P97)Cloth production,QCFood production,QFQDIndifference curvesFood importsCloth exportsIf the relative price of cloth,PC/PF,increases,the economys consumption choice shifts from D1 to D2.lThe move from D1 to D2 reflects two effects:Income ef
9、fect Substitution effectlIt is possible that the income effect will be so strong that when PC/PF rises,consumption of both goods actually rises,while the ratio of cloth consumption to food consumption falls.TTFigure 5-4:Effects of a Rise in the Relative Price of Cloth(P98)Q1VV1(PC/PF)1Q2VV2(PC/PF)2D
10、2D1 Cloth production,QCFood production,QFlThe Welfare Effect of Changes in the Terms of TradeTerms of trade lThe price of the good a country s exports divided by the price of its imports.(P94)lA rise in the terms of trade increases a countrys welfare,while a decline in the terms of trade reduces its
11、 welfare.(P98)发达国家和发展中国家19721993年的贸易条件（单位出口价值/单位进口价值，1972年为100）年度7273747576777879808182发展中国家石油出口国100 113 258 246 259 272 248 302 412 451 450其他国家100 104 999094102 9694918584发达国家100 98878988868986807980年度8384858687888990919293发展中国家石油出口国410412391206232192214243214201198其他国家8487858788929192929291发达国家828
12、1829077919191929494lDetermining Relative PricesSuppose that the world economy consists of two countries:lHome(which exports cloth)Its terms of trade are measured by PC/PF Its quantities of cloth and food produced are QC and QFlForeign(which exports food)Its terms of trade are measured by PF/PC Its q
13、uantities of cloth and food produced are Q*C and Q*FTo determine PC/PF,one must find the intersection of world relative supply of cloth and world relative demand.lThe world relative supply curve(RS)is upward sloping because an increase in PC/PF leads both countries to produce more cloth and less foo
14、d.lThe world relative demand curve(RD)is downward sloping because an increase in PC/PF leads both countries to shift their consumption mix away from cloth toward food.Figure 5-5:World Relative Supply and Demand(P99)RSRDRelative priceof cloth,PC/PFRelative quantityof cloth,QC+Q*C QF+Q*F(PC/PF)11lEcon
15、omic Growth:A Shift of the RS CurveIs economic growth in other countries good or bad for our nation?lIt may be good for our nation because it means larger markets for our exports.lIt may mean increased competition for our exporters.Is growth in a country more or less valuable when that nation is par
16、t of a closely integrated world economy?lIt should be more valuable when a country can sell some of its increased production to the world market.lIt is less valuable when the benefits of growth are passed on to foreigners rather than retained at home.lGrowth and the Production Possibility FrontierEc
17、onomic growth implies an outward shift of a countrys production possibility frontier(TT).Biased growthlTakes place when TT shifts out more in one direction than in the other(P100)lCan occur for two reasons:Technological progress in one sector of the economy Increase in a countrys supply of a factor
18、of productionFigure 5-6:Biased Growth(P100)TT1TT1TT2TT2Cloth production,QCFood production,QF(a)Growth biased toward clothCloth production,QCFood production,QF(b)Growth biased toward foodlRelative Supply and the Terms of TradeExport-biased growthlDisproportionately expands a countrys production possi
19、bilities in the direction of the good it exports(P101)lWorsens a growing countrys terms of trade,to the benefit of the rest of the worldImport-biased growthlDisproportionately expands a countrys production possibilities in the direction of the good it importslImproves a growing countrys terms of tra
20、de at the rest of the words expenseFigure 5-7:Growth and Relative Supply(P102)Relative priceof cloth,PC/PFRelative quantityof cloth,QC+Q*C QF+Q*FRS1RD1(PC/PF)1RS2(PC/PF)22Relative priceof cloth,PC/PFRelative quantityof cloth,QC+Q*C QF+Q*FRS2RD2(PC/PF)2RS1(PC/PF)11(a)Cloth-biased growth(b)Food-biased
21、 growthlInternational Effects of GrowthExport-biased growth in the rest of the world improves our terms of trade,while import-biased growth abroad worsens our terms of trade.Export-biased growth in our country worsens our terms of trade,reducing the direct benefits of growth,while import-biased grow
22、th leads to an improvement of our terms of trade.Immiserizing growthlA situation where export-biased growth by poor nations can worsen their terms of trade so much that they would be worse off than if they had not grown at all(P102)lIt can occur under extreme conditions:Strongly export-biased growth
23、 must be combined with very steep RS and RD curves.lIt is regarded by most economists as more a theoretical point than a real-world issue.Table 5-1:Average Annual Percent Changes in Terms of TradelInternational transfers of income,such as war reparations and foreign aid,may affect a countrys terms o
24、f trade by shifting the world relative demand curve.lRelative world demand for goods may shift because of:Changes in tastesChanges in technologyInternational transfers of incomelThe Transfer ProblemHow international transfers affect the terms of tradelEffects of a Transfer on the Terms of TradeWhen
25、both countries allocate their change in spending in the same proportions(Ohlins point):lThe RD curve will not shift,and there will be no terms of trade effect.When the two countries do not allocate their change in spending in the same proportions(Keyness point):lThe RD curve will shift and there wil
26、l be a terms of trade effect.The direction of the effect on terms of trade will depend on the difference in Home and Foreign spending patterns.Figure 5-8:Effects of a Transfer on the Terms of Trade(P106)Relative priceof cloth,PC/PFRelative quantityof cloth,QC+Q*C QF+Q*FRSRD2RD1(PC/PF)221(PC/PF)1lMar
27、ginal Propensity to Spend:the change of a countrys expenditure divided by the change of its income.lA transfer worsens the donors terms of trade if the donor has a higher marginal propensity to spend on its export good than the recipient.(P106)lIf the donor has a lower marginal propensity to spend o
28、n its export good than the recipient,its terms of trade will actually improve.lPresumptions about the Terms of Trade Effects of TransfersA transfer will worsen the donors terms of trade if the donor has a higher marginal propensity to spend on its export good than the recipient.In practice,most coun
29、tries spend a much higher share of their income on domestically produced goods than foreigners do.lThis is not necessarily due to differences in taste but rather to barriers to trade,natural and artificial.非石油国的发展中国家的贸易条件（1980100）1980100198195.0198294.4198393.5198495.1198592.8lImport tariffs(P109)an
30、d export subsidies(P109)affect both relative supply and relative demand.lRelative Demand and Supply Effects of a TariffTariffs drive a wedge between the prices at which goods are traded internationally(external prices)and the prices at which they are traded within a country(internal prices).The term
31、s of trade correspond to external,not internal,prices.5-3 Tariffs and Export Subsidies:Simultaneous Shifts in RS and RDFigure 5-9:Effects of a Tariff on the Terms of Trade(P110)Relative priceof cloth,PC/PFRelative quantityof cloth,QC+Q*C QF+Q*FRS1RD1RD2RS2 (PC/PF)11(PC/PF)22lEffects of an Export Sub
32、sidyTariffs and export subsidies are often treated as similar policies but they have opposite effects on the terms of trade.lExample:Suppose that Home offers 20%subsidy on the value of cloth exported:This will raise Homes internal price of cloth relative to food by 20%.This will lead Home producers
33、to produce more cloth and less food.lA Home export subsidy worsens Homes terms of trade and improves Foreigns.(P111)Figure 5-10:Effects of a Subsidy on the Terms of Trade(P111)Relative priceof cloth,PC/PFRelative quantityof cloth,QC+Q*C QF+Q*FRS1RD1RD2RS2(PC/PF)11(PC/PF)22lImplications of Terms of T
34、rade Effects:Who Gains and Who Loses?The International Distribution of Income(p111)lIf Home(a large country)imposes a tariff,its welfare increases as long as the tariff is not too large,while Foreigns welfare decreases.lIf Home offers an export subsidy,its welfare deteriorates,while Foreigns welfare
35、 increases.The Distribution of Income Within Countries(p112)lA tariff(subsidy)has the direct effect of raising the internal relative price of the imported(exported)good.lTariffs and export subsidies might have perverse effects on internal prices(Metzler paradox).(p112)lThe standard trade model provi
36、des a framework that can be used to address a wide range of international issues and admits previous trade models as special cases.lA countrys terms of trade are determined by the intersection of the world relative supply and demand curves.lEconomic growth is usually biased.Growth that is export-bia
37、sed(import-biased)worsens(improves)the terms of trade.lInternational transfers of income may affect a countrys terms of trade,depending if they shift the world relative demand curve.lImport tariffs and export subsidies affect both relative supply and demand.lThe terms of trade effects of an export s
38、ubsidy hurt the exporting country and benefit the rest of the world,while those of a tariff do the reverse.Both trade instruments have strong income distribution effects within countries.Figure 5A-1:Homes Desired Trade at a Given Relative PriceTDesiredimportsof foodDesiredexportsof clothHomesimports
39、,DF-QFHomesexports,QC-DCOPC/PFAppendix:Representing International Equilibrium with Offer CurvesFigure 5A-2:Homes Offer CurveCT2T1Appendix:Representing International Equilibrium with Offer CurvesHomesimports,DF-QFHomesexports,QC-DCOFigure 5A-3:Foreigns Offer CurveFAppendix:Representing International
40、Equilibrium with Offer CurvesForeignsexports,Q*F D*FForeignsimports,D*C Q*COAppendix:Representing International Equilibrium with Offer CurvesFigure 5A-4:Offer Curve EquilibriumCFXYEHomes exports of cloth,QC DCForeigns imports of cloth,D*C Q*COHomes imports of food,DF QFForeigns exports of cloth,Q*F D*FlP115,4
