测度中国与G-7的双边贸易成本--一个改进引力模型方法的应用

Measuring the Bilateral Trade Costs between China and G-7:A Revised Gravity Model

传统引力模型方法在测度贸易成本时，由于缺乏微观理论基础，往往事前假定贸易成本的构成并且忽略多边阻力的影响而广受批评。基于一个融入双边冰山型贸易成本的多边一般均衡贸易模型，本文采用的改进引力模型能够弥补上述缺陷。运用该模型我们综合测度了1980～2006年中国与G-7各国关税等价的双边贸易成本。结果表明，中国与这些国家关税等价的贸易成本都已经低于50％，与1980年相比，到2006年平均下降幅度高达30％，并且在入世以后呈现加速下降的趋势。这充分说明近30年来，中国的对外开放程度不断提升，正加速融入全球经济一体化之中。

The traditional gravity model is broadly criticized when it is used to measure trade costs, because it is short of a micro-founded theory and by ex ante assuming trade costs consisted of certain components and without accounting for the impact of multilateral resistance. Based on a revised gravity model which is developed through a multi-country general equilibrium model of trade that incorporates bilateral iceberg trade costs, this paper can overcome above drawbacks. According to the model, we comprehensively measure the tariff equivalent bilateral trade costs between China and G-7 during 1980～2006. The results show that, the tariff equivalent bilateral trade costs between China and G-7 is under 50 percent in 2006 and fell by 30 percent from 1980 to 2006. Especially after accession to WTO, the trend is accelerated to decline.