國際貿易國貿課第1章

1、CHAPTER 1比較優(yōu)勢理論THEORY OF COMPARATIVE ADVANTAGEKEY WORDS:Mercantilism重商主義absolute advantage絕對優(yōu)勢classic theory spelization古典理論專業(yè)化假定amptioncomparative advantage比較優(yōu)勢price ratios equilibrium價格比率均衡opportunity cost機會成本productionsibilities curve 生產可能性曲線marginal rate of substitution邊際替代率slope斜率to be tangent切

2、線, 正切increasing opportunity cost 機會成本遞增demand preference需求偏好indifference curve無差異曲線1.41.5roductionThe Mercantilists Views on TradeTrade Based on Absolute Advantage: Adam Smith Trade Bases on Comparative Advantage: David Ricardo Ricardos Constant Opportunity Costs AndThe Production-sibilitie

3、s Curve1.6Increasing Opportunity Costs AndThe Production-sibilities Curve一.二.三.四.國際貿易理論的分析思路重商主義理論.的絕對優(yōu)勢理論的比較優(yōu)勢理論五.六.機會成本不變條件下的貿易利益機會成本遞增條件下的貿易利益一.國際貿易理論的分析思路國際貿易理論包括兩個基本部分：國際貿易產生的原因和結果?；蛘撸簢H貿易利益是如何產生的，又是如何分配的。We can easily find of the same products bett the main cause of IT is the price difference

4、n two countries. It is profitable.兩個國家生產同樣產品存在價格差異。國際貿易理論就是價格差異產生的原因，供求分析是基本方法。From the poof supply, the price difference isresulted from thedifferent opportunity costs.Productive technology Factor endowment Economies of scale costs priFrom the poof demand, the price differencedepends on bothdemand

5、preference ande.二. The Mercantilists Views on Trade重商主義理論（觀點）三.的絕對優(yōu)勢理論Trade Based on Absolute Advantage: Adam SmithIn his Wealth of Nations (1776), he said:It isof every prudent master of a family, never to attemptto make at home what it will cost him more to maken to buy. Thetailor does notempt to

6、make his own shoes, but buy them from theshoemaker.What is prudencehe conduct of every private family, can scarcebe follyhat of a great kingdom. If a foreign country can supply uswicommodity chern we ourselves can make it, better buy itof them with some part of the product of our own industry, emplo

7、yedin a way in which wee some advantage.“每一個精明的家長都會遵循以下準則：從不在家里生產那些比還貴的產品。裁縫不會試圖自己做鞋，而是從鞋匠哪里買鞋在每一個私人家庭的行為中是精明的事，在一個大國的行為中不大會是荒唐的。如果外國能以比自己制造還便宜的商品供應，那么，最好就用。”具有某些優(yōu)勢的行業(yè)中生產出來的部分產品來向他們The law of absolute advantage: absolute advantage comes from theabsolute difference of productivities based on the abso

8、lute difference of technologies. A nation should produce and export the commodities ofabsoluteadvantage,andimportthecommoditiesofabsolutedisadvantage.“絕對優(yōu)勢”理論（原因和結論）：各國間存在的生產技術上的差別，以及由此造成的勞動生產率和生產成本的絕對差別，是國際分工和國際貿易的基礎。各國應集中生產并出口具有“絕對優(yōu)勢”的產品，進口其不具有“絕對優(yōu)勢”的產品，其結果比自己什么都生產更有利。下面分析“絕對優(yōu)勢”是如何產生的：How to deter

9、mine the absolute advantage in productive technology? The direct way is “productivity”.在勞動是唯一投入的情況下，生產技術的優(yōu)劣可以用勞動生產率來衡量。The A.A theory is based on the following amptions:1.There are two nations (Nation 1 and Nation 2), two commodities(commodity X and commodity Y).2.3.4.Lathe only input.Nations use th

10、e different technology in production.Both commodities are produced under constant returns to scale in both nations.Tastes are equal in both nations.There is perfect competition in both commodities in both nations.5.6.7.There is perfect mobility within each nation but nofactor mobility.ernational8.Th

11、ere are no transporion costs, tariffs, or other obstructions tothe free flow ofernational trade.9.All resourare fully employed in both nations.10.ernational trade betn the two nations is balanced.Table1-1Case of Absolute Advantagehe U.S.In China11小麥布2 hours4 hours2.5 hours 1 hours在封濟中，價格是兩種商品的比價。Tab

12、le 1-2he U.S.In ChinaWithout Trade Price of wheat Price of cloth0.5 布/1 麥2.0 麥/1 布2.5 布/1 麥0.4 麥/1 布商人在國內以 0.5 的布換得的小麥到中國換的了一個的同成類產品，2.5 布，然后把布運回本為零）。，可以換 5 個小麥。（假定So, countries would spelizeheir production.So, both countries can gain from spelizing and trading.注意：此處的貿易利益是指的靜態(tài)利益，是指貿易國在既定的要素供給下或在資源不變

13、的條件下所能獲得的產出和福利的增長情況。包括兩方面：1. 來自于專業(yè)化的利益，指各國通過參與國際分工，專門從事其效率相對最高的生產來獲得額外的利益，提高的利用效率。2.來自于交換的利益。指通過貿易可買到本國不能生產或生產成本太高的產品，使消費的選擇性增加，福利改善。四.的比較優(yōu)勢理論Trade Bases on Comparative Advantage: David Ricardo的比較優(yōu)勢理論解決了這個問題。他認為，如同一個人，一個國家通過在生產率方面具有最大比較優(yōu)勢的商品或服務的出口以及進口其比較優(yōu)勢較小的商品而從貿易中獲利。下面分析比較優(yōu)勢如何產生的：Comparativeadvant

14、agecomesfromtherelativedifferenceoftechnology, and it is measured by relative productivity.產品的比較優(yōu)勢來自于生產技術的相對差別，可以用產品的相對勞動生產率來衡量。相對勞動生產率是不同產品的勞動生產率的比率。產品 A 的相對勞動生產率=產品 A 的人均產量其他產品的人均產量產品 A 的相對生產成本=產品 A 的成本其他產品的成本So,evenif onenation were themost productiveat producing everything and another were the l

15、east, they would both gain by tradingwith each other as long as theye comparative advantage.The law of comparative advantage: comparative advantage comes from the relative difference of productivities based on the relative difference of technologies. A nation should produce and export the commoditie

16、s of comparative advantage, and import the commodities of comparative disadvantage.比較優(yōu)勢理論：如果各國之間存在著勞動生產率的相對差別，就會出現(xiàn)生產成本的相對差別，從而使各國在不同的產品上具有比較優(yōu)勢。各國應該集中生產并出口其具有比較優(yōu)勢的產品，進口其具有比較劣勢的產品。（原因和結論）。Table 1-3 Labor costhe U.S.In China1 wheat1 cloth2 hours1.5 hours4 hours1hour在封濟中，價格是兩種商品的比價。Table 1-4he U.S.InChi

17、naWith no trade Price of wheat Price of cloth0.5 布/1 麥2.0 麥/1 布1.5 布/1 麥0.67 麥/1 布貿易的結果，益。獲得 1 個布的凈收益，中國獲得 1.33 的小麥的凈收Both counties gain from trade and from spelization. (貿易的靜態(tài)利益)。（please see the example, lawyer and secretaryextbook）.五. 機會成本不變條件下的貿易利益Ricardos Constant Opportunity CostsAnd The Produc

18、tion-sibilities Curve定義：機會成本是生產某種產品而必須放棄的能夠生產除此以外最大可獲收益的產品的代價。盡管機會成本不變是不現(xiàn)實的，從理論分析的邏輯來說，要求先分析機會成本不變條件下如何通過國際貿易獲利；然后分析機會成本遞增時如何從貿易中獲利。Table 1-5Units of beef 100Units of wine 50U. S.France50150Figure 1.1U.S. PP curveFigure 1.2 France PP curve:beef452527.5wine751 個酒的機會成本是 2 個牛肉；法國是 1/3 個牛肉。由圖可知，在生產可能性曲線

19、的斜率是 -2，法國是 1/3。由于機會成本不變，Now, we get a key word: Marginal rate of substitution in production (MRSp). 生產的邊際替代率。在完全競爭下，交換的邊際替代率（MRSt）等于生產的邊際替代率(MRSp)。由于兩國 MRSp 不同，存在價格差異，這就是貿易的基礎。Figure 1.3U.S. GainsFigure 1.4 France Gains604040110結果，兩國專業(yè)化生產，然后交換，其消費都超出封閉生產時的生產可能性曲線。dcIn, both countries gain from trad

20、e; because of spelization,their total output of beef and wine is highern before, and the extraoutput of production is shared by consumers in both countries.六.機會成本遞增條件下的貿易利益Increasing Opportunity Costs AndThe Production-sibilities Curve機會成本遞增的兩個原因：不同的產品需要不同的要素密度；而且各種要素只能部分地互相替代?，F(xiàn)在假定機會成本遞增。We can see

21、it clearly. From N to M, the curve slope will and flatter.斜率的絕對值越來越小，價格曲線越來越平緩。e flatter開始時，酒的機會成本大，牛肉的機會成本??；隨著生產點的移動，牛肉的機會成本越來越大，價格越來越高，而酒的機會成本卻越來越小。在機會成本遞增條件下，是什么費者的需求偏好。決定了酒和肉的價格比率？是消假定愿意消費酒和較少肉，選擇 C 點。均衡的條件：生產可能性曲線、價格交換線和無差異曲線相切。因為無差異曲線的任何一點都是消費的邊際替代率(MRSc)，所以，三條線相切，就是：MRSp = MRSc = MRSt .Figure

22、 1.5Increasing Opportunity CostsMbeef0wN假定消費者改變了偏好，愿意消費較多的肉和較少的酒，一條新的無差異曲線將在 D 點與 PP 曲線相切。與 C 點相比，消費了較多的肉和較少的酒?，F(xiàn)在分析在機會成本遞增條件下，和法國如何通過貿易獲利。貿易之前，肉價低，酒價高。開展貿易之后，法國的情況則相反。出口肉，進口酒。為了多出口牛肉，必須多生產牛肉，生產從 C 點貿易開始以后，移到 A 點。出口 DC牛肉，進口 AD 酒。消費點在 C，高于貿易之前的無差異曲線。DTCwineFigure 1.6U.S. Gains from Trade: Increasing Opportunity CostsbeefADCCwineFigure 1.7France Gains from Trade: Increasing Opportunity CostsKJKH法國的情況剛好相反，同學自己分析。最后滿足均衡