6规模经济 不完全竞争和国际贸易.PPTVIP

YOU ARE WELCOME ! International Economics 国际经济学 主讲：余道先 ydxdhy@ Chapter 6 Economies of Scale，Imperfect Competition, and International Trade 规模经济、不完全竞争和国际贸易 Preview Introduction 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 Introduction Countries engage in international trade for two basic reasons: Countries trade because they differ either in their resources or in technology. Countries trade in order to achieve scale economies or increasing returns in production. Introduction （cont.） The Ricardian and Heckscher-Ohlin models also rely on competition to predict that all income from production is paid to owners of factors of production: no “excess” or monopoly profits exist. But when economies of scale exist, large firms may be more efficient than small firms, and the industry may consist of a monopoly or a few large firms. Production may be imperfectly competitive in the sense that excess or monopoly profits are captured by large firms. Introduction （cont.） Two models of international trade in which economies of scale and imperfect competition play a crucial role: Monopolistic competition model（垄断竞争模型） Dumping model（倾销模型） Economies of Scale and International Trade: An Overview Models of trade based on comparative advantage (e.g. Ricardian model) used the assumptions of constant returns to scale and perfect competition: Increasing the amount of all inputs used in the production of any commodity will increase output of that commodity in the same proportion（增加生产某商品所需的所有要素的投入会使该产品的产量同比例增加）. Economies of Scale and International Trade: An Overview In practice, many industries are characterized by economies of scale (also referred to as increasing returns). Production is most efficient, the larger the scale at which it takes place（规模越大，