企业异质性、贸易成本与中国出口增长的二元边际

The Heterogeneity of Firms, the Cost of Trade, and the Dual Margin of the Growth of China's Export

中国出口爆炸式的增长及其表现出来的强劲竞争力已经由一个区域性问题演变成一个世界性问题。本文采用一个企业异质性贸易模型分析框架，从企业层面的微观角度出发，将中国出口总量增长分解为集约的贸易边际与扩展的贸易边际，并在此基础上模拟了可变贸易成本和出口固定成本对二元边际的影响。结果表明，在2003～2006年间，中国的出口扩张主要源自集约的贸易边际，而贸易成本的变动对中国出口总量增长的影响主要是通过促进扩展的贸易边际实现的。由于集约的贸易边际可能导致出口收入波动和贸易条件的恶化，因此本文的主要政策含义在于，中国的出口增长路径必须由集约的贸易边际尽快转向扩展的贸易边际。

China's export boom, a regional problem, has become a world issue. By the use of an analytical framework of enterprise'heterogeneous trade model, starting from the level of enterprises, i. e. from micro-examination, we have, in this paper, decomposed China's aggregate export growth margin into the intensive margin of trade and the extensive margin of trade and then simulated the impact of variable trade cost and the export fixed cost on the dual margin. The results show that, during 2003~2006, China's export growth resulted mainly from the growth of the intensive margin, and the impact of the change in trade costs on the growth of China's aggregate export was materialized mainly by the promotion of the extensive margin of trade. The main policy-implication of this paper is: because the intensive trade margin may lead to fluctuations in income from export and to deterioration of trade conditions, the way to the growth of China's export is that China's intensive trade margin must be trans- formed, as quick as possible, into the extensive trade margin.