[经济学]国际贸易ch课件.ppt

1、2022-8-9华中科技大学经济学院 刘海云1n5.1 Assumption of the Theoryn5.2 The Modeln5.3 Factor-Price Equalization Theoryn5.4 The Leontief Paradox2022-8-9华中科技大学经济学院 刘海云2nExplain the basis of comparative advantagenAnalyze the effect that international Trade has on the earnings of factors of production in the two tradi

2、ng nations.2022-8-9华中科技大学经济学院 刘海云3n1.There are two nations(Nation 1 and Nation 2),two commodities(commodity X and commodity Y),and two factors of production(labor and capital).n2.Both nations use the same technology in production.2022-8-9华中科技大学经济学院 刘海云4n3.Commodity X is labor intensive and commodity

3、 Y is capital intensive in both nations.Commodity X requires relatively more labor to produce than commodity Y in both nations.That is,labor-capital ratio(L/K)is higher for commodity X than for commodity Y in both nations at the same relative factor price.2022-8-9华中科技大学经济学院 刘海云5n4.Both commodities a

4、re produced under constant returns to scale in both nations.n5.There is incomplete specialization in production in both nations.n6.Tastes are equal in both nations.2022-8-9华中科技大学经济学院 刘海云6n7.There is perfect competition in both commodities and factor markets in both nations.n8.There is perfect factor

5、 mobility within each nation but no international factor mobility.2022-8-9华中科技大学经济学院 刘海云7n9.There are no transportation costs,tariffs,or other obstructions to the free flow of international trade.n10.All resources are fully employed in both nations.n11.International trade between the two nations is

6、balanced.2022-8-9华中科技大学经济学院 刘海云8n5.2.1 Factor Intensity We say that commodity Y is capital intensive if capital-labor ratio(K/L)used in the production of Y is greater than K/L used in the production of X.2022-8-9华中科技大学经济学院 刘海云92022-8-9华中科技大学经济学院 刘海云10 There are two ways to define factor abundance.On

7、e way is in terms of physical units(i.e.,in terms of the overall amount of capital and labor available to each nation).Another way to define factor abundance is in terms of relative factor prices(i.e.,in terms of the rental price of capital and the price of labor time in each nation).2022-8-9华中科技大学经

8、济学院 刘海云11n1.Nation 2 is capital abundant if the ratio of the total amount of capital to the total amount of labor(TK/TL)available in nation 2 is greater than that in Nation 1(physical units).n2.Nation 2 is capital abundant if the ratio of rental price of capital to the price of labor(PK/PL)is lower

9、in Nation 2 than in Nation 1(factor price).2022-8-9华中科技大学经济学院 刘海云12 n5.3.1 Introduction 2022-8-9华中科技大学经济学院 刘海云13 nA nation will export the commodity whose production requires the intensive use of the nations relatively abundant and cheap factor and import the commodity whose production requires the

10、intensive use of the nations relatively scarce and expensive factor.In short,the relatively labor-rich nation exports the relatively labor-intensive commodity and imports the relatively capital-intensive commodity.2022-8-9华中科技大学经济学院 刘海云14n5.3.4 Illustration of the H-O Theory2022-8-9华中科技大学经济学院 刘海云152

11、022-8-9华中科技大学经济学院 刘海云16 n例：技术系数技术系数要素价格要素价格成本差距表成本差距表商品YX商品商品YX商品I国II国(1)技术系数技术系数劳动劳动(A)资本资本(B)(2)要素价格要素价格劳动劳动(W)资本资本(R)(3)成本成本P=WA+RB 0.75 0.25 0.25 0.7540日元日元 200日元日元40日元日元 200日元日元PX=80日元日元 PY=160日元日元 0.75 0.25 0.25 0.751美元美元1美元美元1美元美元1美元美元Px=1美元美元Py=1美元美元2022-8-9华中科技大学经济学院 刘海云17nI国用大写母、II国用小写字母来表

12、示。X商品不加撇，Y商品则加撇。在一般情况下，大写字母、不加撇就是在说明I国X商品。现在假定商品成本P可以按下式计划：P=WA+RB（1）n这里A和B是每单位产品所需要的劳动量和资本量，W是劳动价格，即工资，R是资本价格，即利润率（=利息率）。2022-8-9华中科技大学经济学院 刘海云18n同时还要做如下假定：1每种商品的生产技术系数两国完全相同。即：A=a，B=b，A=a，B=b（2）因此这种情况称为“同一技术系数”即：，b/aB/A21/ab/AB212022-8-9华中科技大学经济学院 刘海云19n2但是同X商品相比，Y商品采取资本密集的技术系数即：（3）n3各国国内生产要素可以自由流

13、动，通过市场的完全竞争，等质的生产要素在各产业部门都得到相同的报酬，不存在工资差异和利润率差异：nW=W，R=R，w=w，r=r（4）21212022-8-9华中科技大学经济学院 刘海云20n4但是劳动和资本的相对价格Q=W/R两国相比，1国劳动较便宜，资本较贵，即：Q=Qq=q（5）2022-8-9华中科技大学经济学院 刘海云21n做了上述准备，根据假定的(3)式和(5)式，最后如能证明I国X商品、II国Y商品具有比较优势就可以了。即证明PX/PYpx/py，换言之能证明PX/PYpx/py0就可以了。根据(1)式：qqaarrQQAARRbrawbrawBRAWBRAW/pp/PP2211

14、yxYX2022-8-9华中科技大学经济学院 刘海云22n再把(2)式和(4)式考虑进去，就成为：)(q)()(Qq)(QAAqqQQAA/pp/PP11112211yxYX2022-8-9华中科技大学经济学院 刘海云23但是根据假定,Qq,所以 (Qq)0,()0,即:(Qq)(11)0(6)因此，最后整个式子是负数。从而证明了 PX/PYpx/py0,即PX/PYpx/py 2022-8-9华中科技大学经济学院 刘海云24 It was Paul Samuelson(1976 Nobel Prize in economics)who rigorously proved this theor

15、em(corollary)(also called H-O-S theorem)2022-8-9华中科技大学经济学院 刘海云25 We can state the factor-price equalization(H-O-S)theorem as follows:International trade will bring about equalization in the relative and absolute returns to homogeneous factors across nations.As such,international trade is a substitut

16、e for the international mobility of factors.2022-8-9华中科技大学经济学院 刘海云26nFor example:Labor in all trading nations will have the same return(wages);capital return will be the same too.2022-8-9华中科技大学经济学院 刘海云27nIn national 1,We know that in the absence of trade the relative price of commodity X is lower in

17、 Nation 1 than in Nation 2 because the relative price of labor,or the wage rate,is lower in Nation 1.As Nation 1 specializes in the production of commodity X(the L-intensive commodity)and reduces its production of commodity Y(the K-intensive commodity),the relative demand for labor rises,causing wag

18、es(W)to rise,while the relative demand for capital falls,causing the interest rate(r)to fall.2022-8-9华中科技大学经济学院 刘海云28 nIf all the assumptions hold.There would be a one to one relationship between w/r and PX/PY.Relative factor-price equalization means and also w/r=(w/r)*see Figure 5-52022-8-9华中科技大学经济

19、学院 刘海云29nAbsolute factor-prices equalization Equation of alsolute factor prices means that free international trade also equalizes the real wages for the same type of labor in the two nations and the real rate of interest for the same type of capital in the two nations.2022-8-9华中科技大学经济学院 刘海云30 proof

20、 Eulers theorem:if constant returns to scale prevail in production and if each factor is rewarded(paid)according to its productivity,the output produced is exhausted and just exhausted.Specifically,the marginal physical product of labor 2022-8-9华中科技大学经济学院 刘海云312022-8-9华中科技大学经济学院 刘海云32n(MPL)times the

21、 amount of labor used in production(L)plus the marginal physical product of capital(MPK)times the amount of capital used in production(K)exactly equals the output produced.The same is true for commodity Y.In equation form,Eulers theorem in the production of commodity X can be expressed as (MPL)(L)+(

22、MPK)(K)=X (5A-1)2022-8-9华中科技大学经济学院 刘海云33nDividing both sides by L and rearranging:X/L=MPL+(MPK)(K)/L(5A-2)nFactoring out MPL:X/L=MPL(1+K/L)(MPK/MPL)(5A-3)2022-8-9华中科技大学经济学院 刘海云34 With trade,Nation 1 produces at point B and Nation 2 produces at point B.Since at points B and B,w/r is the same in both

23、nations,MPK/MPL is also the same in both nations.We also know that at points B and B,K/L in the production of commodity X is the same in both nations.2022-8-9华中科技大学经济学院 刘海云35 Finally,X/L is the average product of labor in the production of commodity Xand this is also the same in the two nations beca

24、use of the assumptions of constant returns to scale and the same technology.As a result,the last remaining component(MPL)in equation 5A-3 must also be the same in the production of commodity X in both nations if Equation 5A-3 is to hold.2022-8-9华中科技大学经济学院 刘海云36nTrade Increases the price of the natio

25、ns abundant and cheap factor and reduces the price of its scarce and expensive factor.nThe real income of Labor and of owners of Capital move in the some direction as the movement in factor prices.2022-8-9华中科技大学经济学院 刘海云37nE.g.developed nations case and developing nations case and the policy implicat

26、ion.nempirical Relevance Sometimes,it is more realistic to say that international trade has reduced,rather than completely eliminated,the international difference in the returns to homogeneous factors.2022-8-9华中科技大学经济学院 刘海云38nThe first empirical test of the H-O model was conducted by Wassily Leontie

27、f.nFor this test,Leontief utilized the input-output table of the U.S.economy to calculate the amount of labor and capital in a representative bundle of$1 million worth of U.S.exports import substitutes for the year 1947.2022-8-9华中科技大学经济学院 刘海云39n5.5.1 The results of the test were startling,U.S.import

28、 substitutes were about 30 percent more K intensive than U.S.exports.Leontief paradoxn5.5.2 Explanations of the Leontief paradox2022-8-9华中科技大学经济学院 刘海云40n1.Skilled Labor Theory(Leontief)Since in 1947 U.S.labor was about three times as productive as foreign labor,the United States was really an L-abun

29、dant nation to U.S.import substitutes.2022-8-9华中科技大学经济学院 刘海云41n2.Human Capital Theory(P.B.Kenen)Human capital refers to the education,job training,and health embodied in workers,which increase their productivity.The implication is that since U.S.labor embodies more human capital than foreign labor,a

30、dding the human capital component to physical capital would make U.S.exports more K intensive relative to U.S.import substitutes.2022-8-9华中科技大学经济学院 刘海云422022-8-9华中科技大学经济学院 刘海云43n3.Theory of Technological Gap(M.U.Posner,W.Gruber,R.Vernon)Technology is the result to invest in R&D,and is also one kind

31、of production factor.Of course there exist comparative technology advantages for the technology gap among nations.2022-8-9华中科技大学经济学院 刘海云44n Factor-intensity reversal refers to the situation where a given commodity is the L-intensive commodity in the L-abundant nation and the K-intensive commodity in the K-abundant nation.2022-8-9华中科技大学经济学院 刘海云45nIllustration of Factor-Intensity Reversal 2022-8-9华中科技大学经济学院 刘海云46