1 应用：国际贸易 Application: International Trade 第9章 Chapter 9 2 国际贸易 International Trade 什么决定一个国家 进口还是出口某一 物品？ What determines whether a country imports or exports a good? 3 国际贸易 International Trade 从各国间的自由贸易 中谁受益谁受损？ Who gains and who loses from free trade among countries? 4 国际贸易 International Trade 哪些是人们用以赞成 限制贸易的论点？ What are the arguments that people use to advocate trade restrictions? 5 没有贸易时的均衡 Equilibrium Without Trade 假设：Assume: ?一个国家与世界隔绝，生产钢铁。 A country is isolated from rest of the world and produces steel. ?钢铁市场由该国的买者和卖者组成。 The market for steel consists of the buyers and sellers in the country. ?该国中没有任何人被允许进口或出口钢铁。 No one in the country is allowed to import or export steel. 6 没有贸易时的均衡 Equilibrium Without Trade... 钢铁价格 Price of Steel 均衡价格 Equilibrium Price 0钢铁数量Quantity of Steel 均衡数量 Equilibrium quantity 国内供给 Domestic supply 国内需求 Domestic demand 生产者剩余 Producer surplus 消费者剩余 Consumer surplus 2 7 没有贸易时的均衡 Equilibrium Without Trade 结果：Results: ?国内价格调整到需求和供给平衡。 Domestic price adjusts to balance demand and supply. ?消费者和生产者剩余之和衡量了买者 和卖者得到的总利益。 The sum of consumer and producer surplus measures the total benefits that buyers and sellers receive. 8 世界价格和比较优势 World Price and Comparative Advantage 如果该国决定开放国际贸易，它会 成为钢铁的进口国还是出口国？ If the country decides to engage in international trade, will it be an importer or exporter of steel? 9 世界价格和比较优势 World Price and Comparative Advantage 比较没有贸易时的某物品的国内价格和该物品的世界价格 就可看出自由贸易的结果。 The effects of free trade can be shown by comparing the domestic price of a good without trade and the world price of the good. The world price refers to the prevailing price in the world markets. ?一个国家或者是某物品的进口国或者是它的出口国。 A country will either be an exporter or an importer of the good. 10 世界价格和比较优势 World Price and Comparative Advantage 如果一个国家具有比较优势，那么国内 价格就低于世界价格，该国就会是这一 物品的出口国。 If a country has a comparative advantage, then the domestic price will be below the world price, and the country will be an exporter of the good. 11 世界价格和比较优势 World Price and Comparative Advantage 如果该国不具有比较优势，那么国内价格 就高于世界价格，该国就会是这一物品的 进口国。 If the country does not have a comparative advantage, then the domestic price will be higher than the world price, and the country will be an importer of the good. 钢铁的价格 Price of Steel 0钢铁的数量 Quantity of Steel 国内需求 Domestic demand 出口国的国际贸易 International Trade in an Exporting Country... 国内供给 Domestic supply 世界价 格 World price 贸易后的价格 Price after trade 出口 Exports 国内需求量 Domestic quantity demanded 国内供给量 Domestic quantity supplied 贸易前的价格 Price before trade 3 13 Price of Steel 0 Quantity of Steel 世界价格 World price 国内需求Domestic demand 自由贸易如何影响出口国的福利 How Free Trade Affects Welfare in an Exporting Country... 国内供给Domestic supply 贸易后价格 Price after trade 贸易前价格 Price before trade A B C D 出口 Exports 14 Price of Steel 0 Quantity of Steel World price Domestic demand 自由贸易如何影响出口国的福利 How Free Trade Affects Welfare in an Exporting Country... Domestic supply Price after trade Price before trade A 贸易前的消费者剩余 Consumer surplus before trade B C 贸易前的生产者剩余 Producer surplus before trade 15 Price of Steel 0 Quantity of Steel 世界价格 World price Domestic demand 自由贸易如何影响出口国的福利 How Free Trade Affects Welfare in an Exporting Country... Domestic supply Price after trade Price before trade A 贸易后的消费者剩余 Consumer surplus after trade C B 贸易后的生产者剩余 Producer surplus after trade D 出口 Exports 16 自由贸易的福利变动：出口国的情况 Changes in Welfare from Free Trade: The Case of an Exporting Country 面积D 表示总剩余增加，并代表从贸易中受益。 The area D shows the increase in total surplus and represents the gains from trade. 贸易前Before Trade贸易后After Trade变动Change 消费者剩余Consumer Surplus A + B A -B 生产者剩余Producer Surplus C B + C + D + (B + D) 总剩余Total Surplus A + B + C A + B + C + D + D 17 自由贸易如何影响出口国的福利 How Free Trade Affects Welfare in an Exporting Country 对出口国的分析得出两个结论： The analysis of an exporting country yields two conclusions: ?该物品的国内生产者状况变好，而国内消费者状况变 坏。 Domestic producers of the good are better off, and domestic consumers of the good are worse off. ?贸易增加了一国的整体的经济福利。 Trade raises the economic well-being of the nation as a whole. 18 国际贸易和进口国 International Trade and the Importing Country 如果世界价格低于国内价格，当贸易 被允许的时候，该国将会成为钢铁的 进口国。 If the world price of steel is lower than the domestic price, the country will be an importer of steel when trade is permitted. 4 19 国际贸易和进口国 International Trade and the Importing Country 国内消费者想买较低的国际价格的 钢铁。 Domestic consumers will want to buy steel at the lower world price. 20 国际贸易和进口国 International Trade and the Importing Country 由于国内价格向国际价格移动，国 内生产者将降低它们的产量。 Domestic producers of steel will have to lower their output because the domestic price moves to the world price. 21 国际贸易和进口国 International Trade and the Importing Country... Price of Steel 0 Quantity of Steel 国内供给 Domestic supply 国内需求 Domestic demand 世界价格 World Price 贸易后价格 Price after trade 国内供给量 Domestic quantity supplied 国内需求量 Domestic quantity demanded 贸易前价格Price before trade 进口 Imports 22 自由贸易如何影响进口国的福利 How Free Trade Affects Welfare in an Importing Country... Price of Steel 0 Quantity of Steel 国内供给Domestic supply 世界价格 World Price 国内需求 Domestic demand 贸易后价格 Price after trade 贸易前价格Price before trade A B C D 进口 Imports 23 自由贸易如何影响进口国的福利 How Free Trade Affects Welfare in an Importing Country... Price of Steel 0 Quantity of Steel 国内供给 Domestic supply 世界价格 World Price 国内需求 Domestic demand 贸易后价格 Price after trade 贸易前价格Price before trade A 贸易前的消费者剩余 Consumer surplus before trade C B 贸易前的生产者剩余 Producer surplus before trade 24 自由贸易如何影响进口国的福利 How Free Trade Affects Welfare in an Importing Country... Price of Steel 0 Quantity of Steel 国内供给 Domestic supply 世界价格 World Price 国内需求 Domestic demand 贸易后价格 Price after trade 贸易前价格Price before trade A 贸易后的消费者剩余 Consumer surplus after trade B D C 贸易前的生产者剩余 Producer surplus after trade Imports 5 25 自由贸易的福利变动：进口国的情况 Changes in Welfare from Free Trade: The Case of an Importing Country 面积D 表示总剩余增加，并代表从贸易中受益。 The area D shows the increase in total surplus and represents the gains from trade. 贸易前Before Trade贸易后After Trade变动Change 消费者剩余Consumer Surplus A A + B + D + (B + D) 生产者剩余Producer Surplus B + C C -B 总剩余Total Surplus A + B + C A + B + C + D + D 26 自由贸易如何影响进口国的福利 How Free Trade Affects Welfare in an Importing Country 对出口国的分析得出两个结论： The analysis of an importing country yields two conclusions: ?该物品的国内生产者状况变坏，而国内消费者状况变好 Domestic producers of the good are worse off, and domestic consumers of the good are better off. ?贸易增加了一国的整体的经济福利。 Trade raises the economic well-being of the nation as a whole because the gains of consumers exceed the losses of producers. 27 自由国际贸易中的得失 The Gains and Losses from Free International Trade ?赢家的好处大于输家的损 失。 The gains of the winners exceed the losses of the losers. ?总剩余的净变动是正的。 The net change in total surplus is positive. ?赢家将补偿输家吗？ Will the winners compensate the losers? 28 关税 Tariffs ?关税是对进口物品征收的税。 Tariffs are taxes on imported goods. ?关税使进口物品的价格提高到世界价格 之上，其增加量等于关税。 Tariffs raise the price of imported goods above the world price by the amount of the tariff. 29 Price with tariff 世界价 格 World price Price without tariff 关税的影响 The Effects of a Tariff... Price of Steel 0 Quantity of Steel 国内供给 Domestic supply 国内需求 Domestic demand 关税Tariff Q 1 S Q 1 D 无关税时的进口Imports without tariff 有关税时的 进口 Imports with tariffQ2 D Q 2 S 30 关税的影响 The Effects of a Tariff... Price of Steel 0 Quantity of Steel 国内供给 Domestic supply 国内需求 Domestic demand 世界价 格 World price Q 1 S Q 1 D 无关税时的价 格Price without tariff 无关税时的进口Imports without tariff 无关税时的消费者剩余 Consumer surplus before tariff 无关税时的生产者剩余 Producer surplus before tariff 6 31 关税的影响 The Effects of a Tariff... Price of Steel 0 Quantity of Steel 国内供给 Domestic supply 国内需求 Domestic demand 关税Tariff 世界价 格 World price Q 1 S Q 2 S Q 2 D Q 1 D Price without tariff Price with tariff 无关税时的进口Imports without tariff 有关税时的 进口 Imports with tariff A 有关税时的消费者剩余 Consumer surplus with tariff B 32 关税的影响 The Effects of a Tariff... Price of Steel 0 Quantity of Steel 国内供给 Domestic supply 国内需求 Domestic demand 关税Tariff 世界价 格 World price Q 1 S Q 2 S Q 2 D Q 1 D 无关税时的进口Imports without tariff 有关税时的 进口 Imports with tariff C G 有关税时生产者剩余 Producer surplus with tariff 33 关税的影响 The Effects of a Tariff... Price of Steel 0 Quantity of Steel Domestic supply Domestic demand T关税ariff World price Q 1 S Q 2 S Q 2 D Q 1 D Imports without tariff Imports with tariff E 关税收入Tariff revenue Price with tariff Price without tariff 34 关税的影响 The Effects of a Tariff... Price of Steel 0 Quantity of Steel Domestic supply Domestic demand 关税Tariff World price Q 1 S Q 2 S Q 2 D Q 1 D Price without tariff Price with tariff 无关税时的进口Imports without tariff 有关税时的 进口 Imports with tariff A B CE G DF 无谓损失Deadweight loss 35 关税引起的福利变动 Changes in Welfare from a Tariff 关税前Before Tariff关税后After Tariff变动Change 消费者剩余Consumer Surplus A+B+C+D+E+F A + B - (C+D+E+F) 生产者剩余Producer Surplus G C + G + C 政府收入 Government Revenue None E + E 总剩余Total Surplus A+B+C+D+E+F+G A+B+ C+ E+ G -(D + F) 面积D +F 表示总剩余减少，并代表关税的无谓损失。 The area D+F shows the fall in total surplus and represents the deadweight loss of the tariff. 36 关税的影响 The Effects of a Tariff ?关税减少了进口量，并使国内市场向没有贸 易时的均衡移动。 A tariff reduces the quantity of imports and moves the domestic market closer to its equilibrium without trade. ?由于关税，市场中的总剩余减少的部分就是 无谓损失。 With a tariff, total surplus in the market decreases by an amount referred to as a deadweight loss. 7 37 进口限(配)额的影响 The Effects of an Import Quota 进口限额是对进口数量的限制。 An import quota is a limit on the quantity of imports. 38 有限额时的价格 Price with quota 世界价格 World price 无限额时的价格 Price without quota 进口限额的影响 The Effects of an Import Quota ... Price of Steel 0 Quantity of Steel 国内供给 Domestic supply 国内需求 Domestic demand Q 1 S Q 2 S Q 2 D 无限额时的进口Imports without quota 有限额时的进口 Imports with quota 国内供给＋进口供给 Domestic supply + Import Supply 限额 Quota 有限额时的均衡 Equilibrium with quota 无贸易时的均衡 Equilibrium without trade Q 1 D 39 进口限额的影响 The Effects of an Import Quota ?由于限额使国内价格上升到世界价格之上，国内买者 的状况变坏了，国内卖者的状况变好了。 Because the quota raises the domestic price above the world price, domestic buyers of the good are worse off, and domestic sellers of the good are better off. ?许可证持有者的状况变好了，因为他们能世界价格购 买并以交高的国内价格出售中获利。 License holders are better off because they make a profit from buying at the world price and selling at the higher domestic price. 40 进口限额的影响 The Effects of an Import Quota ... Price of Steel 0 Quantity of Steel 国内供给 Domestic supply 国内需求 Domestic demand 世界价格 World price Q 1 S Q 2 S Q 2 D Q 1 D 无限额时的价格 Price without quota 有限额时的价格 Price with quota 无限额时的进口Imports without quota 有限额时的进口 Imports with quota 国内供给＋进口供给 Domestic supply + Import Supply 限额 Quota A B CE ' E '' F G D 41 进口限额引起的福利变动 Changes in Welfare from an Import Quota A+B+C+D+E’+E”+F+G A+B+C+E’+E”+G 面积D+F 表示总剩余的减少，代表进口限额的无谓损失 The area D+F shows the fall in total surplus and represents the deadweight loss of the quota. 限额前Before Quota限额后After Tariff变动Change 消费者剩余 Consumer Surplus 生产者剩余 Producer Surplus Total Surplus A+B+C+D+E’+E”+F A+B -(C+D+E’+E”+F) G C+G +C None E’+E” +(E’+E”) -(D+F) 许可证持有者剩余许可证持有者剩余 License holder Surplus 42 进口限(配)额的影响 The Effects of an Import Quota ?进口限额使的市场中的总剩余减少，减少的这部分 被称为无谓损失。 With a quota, total surplus in the market decreases by an amount referred to as a deadweight loss. ?进口限额有可能引起更大的无谓损失，如果分配进 口许可证的机制中包含诸如游说这类的活动。 The quota can potentially cause an even larger deadweight loss, if a mechanism such as lobbying is employed to allocate the import licenses. ?这是因为游说有成本。 This is because lobbying has a cost. 8 43 关税和进口限额的影响 The Effects of Tariffs and Quotas 如果政府以全价出售进口许可证，政 府的收入等于等价的关税收入，那么 关税和进口限额就完全相同。 If government sells import licenses for full value, revenue equals that of equivalent tariff and the results of tariffs and quotas are identical. 44 关税和进口限额两者都 Both tariffs and import quotas …提高国内价格 raise domestic prices. …减少国内消费者的福利 reduce the welfare of domestic consumers. …增加国内生产者的福利 increase the welfare of domestic producers. …导致无谓损失 cause deadweight losses. 45 国际贸易的其他好处 Other Benefits of International Trade ?增加物品的多样性 Increased variety of goods ?通过规模经济降低成本 Lower costs through economies of scale ?增加竞争 Increased competition ?加强思想交流 Enhanced flow of ideas 46 各种限制贸易的论点 The Arguments for Restricting Trade ?工作岗位论Jobs ?国家安全论National Security ?幼稚产业论Infant Industry ?不公平竞争论Unfair Competition ?保护作为讨价还价筹码论 Protection as a Bargaining Chip 47 总结 Summary ?通过比较没有国际贸易时的国内价格和世界价格，可以 确定自由贸易的影响。 The effects of free trade can be determined by comparing the domestic price without trade to the world price. ?国内价格低表明，该国在生产这种物品上有比较优势， 而且该国将成为出口者。 A low domestic price indicates that the country has a comparative advantage in producing the good and that the country will become an exporter. ?国内价格高表明，世界其他国家在生产这种物品上有比 较优势，而且，该国将成为出口者。 A high domestic price indicates that the rest of the world has a comparative advantage in producing the good and that the country will become an importer. 48 总结 Summary ?当一国允许贸易并成为一种物品的出口者时，该物品 的生产者状况变好，而该物品的消费者状况变坏。 When a country allows trade and becomes an exporter of a good, producers of the good are better off, and consumers of the good are worse off. ?当一国允许贸易并成为一种物品的进口者时，该物品 的消费者状况变好，而该物品的生产者状况变坏。 When a country allows trade and becomes an importer of a good, consumers of the good are better off, and producers are worse off. 9 49 总结 Summary ?关税––对进口征税––使市场向没有贸易时存在 的均衡移动，因此减少了贸易的好处。 A tariff – a tax on imports – moves a market closer to the equilibrium than would exist without trade, and therefore reduces the gains from trade. ?进口限额的影响与关税相似。 Import quotas will have effects similar to those of tariffs. 50 总结 Summary ?有各种限制贸易论：保护工作岗位，保卫国家安全，有 助于幼稚产业，防止不公平竞争，以及对外国的贸易限 制作出反应。 There are various arguments for restricting trade: protecting jobs, defending national security, helping infant industries, preventing unfair competition, and responding to foreign trade restrictions. ?但是经济学家相信，自由贸易通常是一种更好的政策。 Economists, however, believe that free trade is usually the better policy.