一、问题的由来在世界经济形成和发展的过程中,自由贸易和保护贸易一直共同或交替成为国际贸易的主导。尽管从亚当·斯密以来一直到近年出现的新贸易理论,都在试图证明自由贸易对各国国民福利的正面影响,但是,贸易保护的理论始终也没有退出流行的国际经济学和国际贸易的实践。当然,在传统的国际贸易理论中,通常的认识是发达国家偏好于自由贸易政策,而相对落后的国家则偏好于用贸易保护政策的 I. Origins of the Problem In the course of the formation and development of the world economy, free trade and protection trade have been the common or alternative trade dominance in international trade. Although the new trade theories that emerged from Adam Smith until recent years are all trying to prove the positive impact of free trade on the national welfare of all countries, the theory of trade protection has never stood out from the practice of popular international economics and international trade . Of course, in the traditional theory of international trade, the common understanding is that the developed countries prefer the free trade policy, whereas the relatively backward countries prefer to use the trade protection policy