Research On New-New Trade Theory And Its Significance For China

International trade theory mainly researches the exchange of goods and services among nations. It focuses on the topic about the reason and pattern of international trade, and the effect on national welfare after international trade, etc, and it also puts forward the appropriate measures to solve them. International trade is the important part of International Economics. The development of the international trade theory can be traced back to Mercantilism of the west in the Middle Ages, which is at the primary stage of development of trade theory. Then Adam Smith's theory of absolute advantage and David Ricardo's theory of comparative advantage birthed, which marked the beginning of forming System of trade theory. After that Eli Heckscher and Bertll Ohin come up with Factor Endowment Theory from the point of resource endowment, which promoted the further development of trade theory. Other theories, such as Product Cycle Theory, Linder Theory, etc, were complements. In the 1980s economists represented by Paul Krugman, taking economies of scale as assumption, creatively put forward new theory-- Intra -industry Trade Theory, which was the revolutionary development of trade theory. After this the development of trade theory was stagnant. Until the 21st century, there appeared Morris's Heterogeneous enterprise model and Bernard's Enterprise endogenous boundary model, and these two theories explain From microcosmic Angle why in the same industry some enterprises engage in international business and others only engage in domestic trade, and the latter explains the issue about definition of enterprise boundary in detail,that is called New-New Trade Theory. It broken up firm 's homogeneity assumption that exists in both traditional trade theory and modern trade theory , bringing heterogeneity into framework of microscopic analysis, and did a lot of empirical analysis to explain the composition of international trade and trade volume. This theory is becoming a hotspot. Although there is no consensus in the theoretical and it is still at the exploratory stage, it has stronger explanation ability and more developmental space.This paper attempts to reveal the whole process of the development of trade theory, and reasons and conditions for change of trade theory at different stages and the reaults of the changing by discussing New-New Trade Theory systematically. By introducing origin and background of new-new trade theory, this paper points out the reasons and conditions for forming the theory and different from traditional theory. With introducing theoretical model of new-new trade, it makes us master the essence of the theory more accurate. With analyzing the characteristic of the theory, it makes us find the value of the theory and take it as theoretical guidance for formulating trade policy.This paper contains four parts. The first part is introduction, which illustrates the development of trade theory, the recent research on new-new trade theory and some basic ideas about writing the article. Then it describes theoretical origins of new-new trade theory, there are there theoretical origins, and they are Ricardo's comparative advantage model, H-O model and Krugman's monopolistic competition model. The third part illuminates the content of new-new trade theory systematically and fully, including features, different from traditional theory, heterogeneity enterprise competition model, enterprise endogenous boundary model, shortages of the theory and so on. The last part tells us the value of the theory and its significance for china.