克鲁格曼英文第七版5.ppt

International Economicstheory and policy Paul R. Krugman Maurice Obstfeld Chaper 5 Economies of Scale, Imperfect Competition, and International Trade Economies of Scale and International Trade: An Overview Economies of Scale and Market Structure The Theory of Imperfect Competition Monopolistic Competition and Trade Dumping The Theory of External Economies External Economies and International Trade Summary Why do Countries Specialize and Trade? First, countries differ either in their resources or in technology and specialize in the things they do relatively well. Second, economies of scale(or increasing returns) make it advantageous for each country to specialize in the production of only a limited range of goods and sevices. Economies of Scale and Imperfect Competition The introduction of the economies of scale will inevitably means that the market is defined as an imperfect competitive market. Economies of scale shows the existence of increasing marginal returns, the existence of the firms’ excessive profits, and the existence of production advantanges of larger firms, so the market will inevitably create monopoly and imperfect competition. 1. Economies of Scale and International Trade: An Overview The economies of scale will gether scattered small-scale production among every countries into a specialized large-scale production in each countries, and thus receive more output than the scattered small-scale production. Each countries specialize producing different goods at the same time, and can enjoy more types and numerous products to consume through international trade. 2. Economies of Scale and Market Structure The economies of scale have two different production increase to reduce average cost: 内部规模经济是指单位产品成本取决于单个厂商的规模而不是所在的行业规模； 外部规模经济是指单位产品成本取决于行业规模而非单个厂商的规模。 Economies of Scale and Market Structure In the external economies of scale industry, the market is often composed of many relatively small firms, and is in a state of perfect competition; In the