国际经济学第3章The-Ricardian-Model(课堂PPT).ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,第三章,李嘉图模型,The Ricardian Model,1,内容：,关于比较优势理论,单一要素经济,单一要素世界中的贸易,贸易所得,多种产品模型中的比较优势,比较优势理论的局限性,对比较优势理论的实证分析,2,问题：,鲁宾逊,每小时可以摘,10,个椰子或捕,3,条鱼，他的朋友,星期五,每小时可摘,30,个椰子或捕,2,条鱼。他们应给如何分工呢？,如果,鲁宾逊,每小时只能摘,10,个椰子或捕,1,条鱼，他们又该如何分工呢？,3,一、关于比较优势理论,David Ricardo,大卫,李嘉图,Principles of Political Economy and Taxation,(1817),4,一、关于比较优势理论,比较优势,comparative advantage,如果一个国家在本国生产一种产品的机会成本低于在其他国家生产该产品的机会成本，则这个国家在生产该产品上拥有,比较优势,。,机会成本,opportunity cost,为得到某种东西所必须放弃的东西。,5,Assumptions of Ricardian Model,Labor is the only resource important for production.,Labor productivity varies across countries,usually due to differences in technology,but labor productivity in each country is constant across time.,The supply of labor in each country is constant.,Only two goods are important for production and consumption:wine and cheese.,Competition allows laborers to be paid a,“,competitive,wage,a function of their productivity and the price of the good that they can sell,and allows laborers to work in the industry that pays the highest wage.,Only two countries are modeled:domestic and foreign.,6,二、单一要素经济,1,、封闭经济条件：,两种商品：奶酪,(cheese),、葡萄酒,(wine),一种生产要素：劳动,(labor),令,L=,本国的劳动总供给,（单位：人小时personhours,）,a,LC,=,在本国生产,1,单位奶酪的劳动投入量,a,LW,=,在本国生产,1,单位葡萄酒的劳动投入量,a,LC,和,a,LW,为,单位产品的劳动投入,unit labor requirement,7,二、单一要素经济,2,、生产可能性：,令,Q,W,=,本国的葡萄酒产量,Q,C,=,本国的奶酪产量,则：,a,LW,Q,W,+a,LC,Q,C,L,充分就业时有：,a,LW,Q,W,+a,LC,Q,C,=,L,即：,Q,W,=,L/a,LW,-,（,a,LC,/a,LW,）,Q,C,生产可能性边界：,production possibility frontier,8,9,Production Possibilities,The production possibility frontier(PPF)of an economy shows the,maximum,amount of a goods that can be produced for a fixed amount of resources.,If,Q,C,represents the quantity of cheese produced and,Q,W,represents the quantity of wine produced,then the production possibility frontier of the domestic economy has the equation:,a,LC,Q,C,+,a,LW,Q,W,=L,Total units of wine production,Labor required for each unit of cheese production,Total units of cheese production,Labor required for each unit of wine production,Total amount of labor resources,10,二、单一要素经济,3,、相对价格与供给,令,P,C为奶酪的价格,P,W,为葡萄酒的价格,P,C,/P,W,为两种产品的,相对价格,relative price,11,二、单一要素经济,当,P,C,/a,LC,P,W,/a,LW,，工人将流向奶酪部门，此时本国只生产奶酪,即：,P,C,/P,W,a,LC,/a,LW,当,P,C,/a,LC,P,W,/a,LW,，工人将流向葡萄酒部门，此时本国只生产葡萄酒,即：,P,C,/P,W,a,LC,/a,LW,当,P,C,/a,LC,=P,W,/a,LW,时，本国将同时生产奶酪和葡萄酒两种产品,即：,P,C,/P,W,=a,LC,/a,LW,12,二、单一要素经济,如果,P,C,/P,W,a,LC,/aLW,，本国就会专门生产奶酪,如果,P,C,/P,W,a,LC,/a,LW,，本国就会专门生产葡萄酒,只有当,P,C,/P,W,=a,LC,/a,LW,时，本国才会生产奶酪和葡萄酒两种产品,13,二、单一要素经济,The economy will specialize in the production of cheese if the relative price of cheese exceeds its opportunity cost;it will specialize in the production of wine if the relative price of cheese is less than its opportunity cost.,In the absence of international trade,the relative prices of goods are equal to their relative unit labor requirements.,14,Problems,Home has 1200 units of labor available.It can produce two goods,apples and bananas.The unit labor requirement in apple production is 3,while in banana production it is 2.,a.,Graph Homes production possibility frontier.,b.,What is the opportunity cost of apples in terms of bananas?,c.,In the absence of trade,what would the price of apples in terms of bananas be?Why?,15,三、单一要素世界中的贸易,1,、贸易之前的情况,（,1,）两个国家：本国和外国,（,Home&Foreign,）,（,2能生产两种产品：奶酪和葡萄酒,（,cheese&wine,）,（,3,）每个国家只有一种生产要素,（,Labor,）,（,4,）令,L=,本国的劳动总供给,L*=,外国的劳动总供给,（,5,）令,a,LC,=,在本国生产,1,单位奶酪的劳动投入量,令,a,LW,=,在本国生产,1,单位葡萄酒的劳动投入量,令,a,LC,*,=,在外国生产,1,单位奶酪的劳动投入量,令,a,LW,*,=,在外国生产,1,单位葡萄酒的劳动投入量,16,假设：,a,LC,a,LW,a,LC,*,a,LW,*,或,a,LC,a,LC,*,a,LW,a,LW,*,如果：,a,LC,a,LC,*,则：本国具有奶酪生产的绝对优势,absolute advantage,17,问题,如果两国各在某一商品上具有绝对优势，那么两国在相应的商品上也必然具有比较优势，这句话对吗？请评论。,18,19,20,21,三、单一要素世界中的贸易,2,、国际贸易均衡,相对供给,(relative supply,，,RS),是用一种产品的供给数量除以另一种产品的供给数量；,相对需求,(relative demand,，,RD),是用一种产品的需求数量除以另一种产品的需求数量。,22,Relative Supply and Relative Demand,To calculate relative prices with tradewe first calculate,relative quantities,of,world,production:,(,Q,C,+Q,*,C,)/(,Q,W,+Q,*,W,),Next we consider relative supply of cheese:the quantity of cheese supplied by all countries relative to the quantity of wine supplied by all countries at each,relative price,of cheese,P,c,/P,W,.,23,24,RD,25,26如果,P,C,/P,W,a,LC,/a,LW,，一国就会专门生产奶酪,如果,P,C,/P,W,a,LC,/a,LW,，一国就会专门生产葡萄酒,只有当,P,C,/P,W,=a,LC,/a,LW,时，一国会同时生产奶酪和葡萄酒两种产品,27,RS,曲线的推导,（,1,）如果,P,C,/P,W,a,LC,/a,LW,，,RS=,？,（,2,）如果,P,C,/P,W,=,a,LC,/a,LW,，,RS=,？,（,3,）如果,a,LC,/a,LW,P,C,/P,W,a,LC,*,a,LW,*,，,RS=,？,（,4,）如果,P,C,/P,W,=,a,LC,*,a,LW,*,，,RS=,？,（,5,）如果,a,LC,*,a,LW,*,P,C,/P,W,，,RS=,？,28,Relative Supply and Relative Demand,There is no supply of cheese if the relative price of cheese falls below,a,LC,/a,LW,.,Why?because the domestic country will specialize in wine production whenever,P,C,/P,W,a,LC,/a,LW,And we assumed that,a,LC,/a,LW,P,c,/P,W,a,LC,/a,LW,domestic workers specialize in cheese production because they can earn higher wages,but foreign workers will still produce only wine.,When,a,*,LC,/a,*,LW,=,P,C,/,P,W,foreign workers will be indifferent between producing wine or cheese,but domestic workers will still produce only cheese.,There is no supply of wine if the relative price of cheese rises above,a,*,LC,/a,*,LW,30,31,32,3,RD,33,34,35,A,B,import,export,36,export,A,import,B,37,export,A*,import,B*,A,B,import,export,38,问题,假设某一国家拥有,20000,单位的劳动，,X,、,Y,产品的单位产出所要求的劳动投入分别为,5,个单位和,4,个单位，试确定生产可能性边界方程。如果,X,的国际相对价格为,2,，该国的进口数量为,2000,个单位，试确定该国的出口量，并在图中画出贸易三角形。,39,四、贸易所得,间接生产的影响,(indirect method of production),（,1,a,LC,）*（,Pc,Pw,）,1,a,LW,或,P,C,/P,W,a,LC,/a,LW,贸易对消费可能性的影响,(consumption possibilities),40,41,四、贸易所得,具体数例,42,相关论点,只有当一个国家的生产率达到足以在国际竞争中立足的水平时，它才能从自由贸易中获益。,43,Problems,1.,Home has 1200 units of labor available.It can produce two goods,apples and bananas.The unit labor requirement in apple production is 3,while in banana production it is 2.There is now also another country,Foreign,with a labor force of 800.Foreigns unit labor requirement in apple production is 5,while in banana production it is 1.,a.,Graph Foreigns production possibility frontier.,b.,Construct the world relative supply curve.,44,Problems,2.,Now suppose world relative demand takes the following form:Demand for apples/demand for bananas =price of bananas/price of apples,a.,Graph the relative demand curve along with the relative supply curve.,b.,What is the equilibrium relative price of apples?,c.,Describe the pattern of trade.,d.,Show that both Home and Foreign gain from trade.,45,五、,多种产品模型中的比较优势,建立模型,（,1,）两个国家：本国和外国,（,Home&Foreign,）,（,2,）一种生产要素：劳动,(labor),（,3,）产品数量,=N,（,4,）令本国某种产品的单位产品劳动投入为,a,Li,，,外国某种产品的单位产品劳动投入为,a,Li,*,（,5,）,a,L1,a,L1,*,a,L2,a,L2,*,a,L3,a,L3,*,a,LN,a,LN,*,或,a,L1,*,a,L1,a,L2,*,a,L2,a,L3,*,a,L3,a,LN,*,a,LN,46,五、,多种产品模型中的比较优势,相对工资和专业分工,令,W,为本国的小时工资率,W,*,为外国的小时工资率,W/W,*,为,相对工资（,relative wage,）,47,五、,多种产品模型中的比较优势,相对工资和专业分工,如果：,W,a,Li,W,*a,Li,*,或,a,Li,*,a,Li,W,W,*,则：,在本国生产产品,i,的成本比较低,如果：,W,a,Li,W,*a,Li,*,或,a,Li,*,a,Li,W,W,*,则：,在外国生产产品,i,的成本比较低,如果：,W,a,Li,=W,*a,Li,*,或,a,Li,*,a,Li,=W,W,*,则：,本国和外国生产产品,i,的成本相等,48,a,Li,*,a,Li,=,（,1/a,Li,）,/,（,1/a,Li,*,）,1/a,Li,为本国,i,产品的劳动生产率，,1/a,Li,*,为外国,i,产品的劳动生产率。因此，,a,Li,*,a,Li,就是相对劳动生产率或本国劳动生产率的相对优势。,49,五、,多种产品模型中的比较优势,相对工资和专业分工,a,L1,*,a,L1,a,L2,*,a,L2,a,L3,*,a,L3,a,LN,*,a,LN,a,L1,*,a,L1,aL2,*,a,L2,a,L3,*,a,L3,W,W,*,a,L,（,N-2,）,*,a,L,（,N-2,）,a,L,（,N-1,）,*,a,L,（,N-1,）,a,LN,*,a,LN,任何符合,a,Li,*,a,Li,W,W,*,条件的产品将在本国生产，而任何符合,a,Li,*,a,Li,W,W,*,条件的产品将在外国生产，当,a,Li,*,a,Li,=W,W,*,时，本国和外国将同时生产此种产品。,50,五、,多种产品模型中的比较优势,本国和外国的单位产品劳动投入,51,五、,多种产品模型中的比较优势,相对工资的确定,劳动的相对供给,是本国劳动的供给量除以外国劳动的供给量；,劳动的相对需求是本国劳动的需求量除以外国劳动的需求量。,劳动需求是商品需求的,派生需求,(derived demand),。,52,53,54,六、,运输费用和非贸易品,生产中多种要素的存在减弱了专业分工的趋势；,有时国家要针对外来竞争保护民族产业；,产品和服务的运输费用昂贵，以至有时运输费用过高，使一些国家不得不在某些产业部门实行自给自足。,55,本国和外国的单位产品劳动投入如下图所示，,a.,当本国的相对工资率为,3,时，世界的生产布局如何？,b.,当两国间的运输费用为生产成本的,100%,时，世界的生产布局如何？,56,七、,总结：对基本贸易问题的答案,1,、国家间发生贸易的原因是什么？,2,、国际贸易遵循怎样的模式？,3,、贸易对各国的生产和消费会产生什么影响？,4,、贸易对各国的整体福利会产生什么影响？,5,、贸易如何影响经济福利或收入在一国之内不同集团之间的分配？,57,李嘉图模型是否反映了现实世界的情况？,李嘉图模型对于实际国际贸易流向的预见是否正确？,58,八、,比较优势理论的局限性,1,、李嘉图模型预测了极端的专业分工，而它在现实世界中根本看不到；,2,、李嘉图模型忽略了国际贸易对国内收入分配的影响；,3,、李嘉图模型忽略了各国资源的不同也是贸易产生的一个原因，因此漏掉了贸易体系的一个重要方面；,4,、李嘉图模型忽视了规模经济也可能是国际贸易的起因，这使它无法解释明显相似的国家之间大量的贸易往来。,59,九、对比较优势理论的实证分析,Bela Balassa,贝拉,巴拉萨,An Empirical Demonstration of Classical Comparative Cost Theory,（,1963,）,60,61,Key Terms,absolute advantage,comparative advantage,derived demand,gains from trade,nontraded goods,opportunity cost,production possibility frontier,relative demand curve,relative supply curve,relative wage,Ricardian model,unit labor requirement,62,The end,63,