国际贸易理论与实务课件6.ppt

Chapter Organization 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. Two models of international trade in which economies of scale and imperfect competition play a crucial role: Monopolistic competition model Dumping model 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: In practice, many industries are characterized by economies of scale. Economies of Scale and International Trade: An Overview Under increasing returns to scale: Output grows proportionately more than the increase in all inputs. Average costs (costs per unit) decline with the size of the market. Economies of Scale and International Trade: An Overview Economies of Scale and Market Structure Economies of scale can be either: External The cost per unit depends on the size of the industry but not necessarily on the size of any one firm. An industry will typically consist of many small firms and be perfectly competitive. Internal The cost per unit depends on the size of an individual firm but not necessarily on that of the industry. The market structure will be imperfectly competitive with large firms having a cost advantage over small. Both types of scale economies are important causes of international trade. The Theory of Imperfect Competition Imperfect competition Each firm views itself as a price setter, choosing the price of its product, rather than a price taker. Firms can sell m