关税对企业贸易边际的异质性影响——基于关税水平和关税政策不确定性的视角

关税是影响企业出口行为决策的重要因素。以中国加入WTO作为准自然实验,基于2000—2006年中国工业企业数据库与海关数据库的匹配数据,采用双重差分法从关税水平和关税政策不确定性两个维度研究了关税下降对企业贸易边际的异质性影响。研究发现,关税水平下降主要导致企业的贸易扩展边际增长,而关税政策不确定性的降低则主要导致企业的集约边际增长。具体来说,关税水平下降得较多的行业,企业的扩展边际增加较多,但相应的集约边际反而增长较少,从而导致总出口减少;关税政策不确定性下降得较多的行业,对美出口的集约边际增加较多,而相应的扩展边际增长较少,从而导致对美总出口增加。研究结论表明,政府可以通过降低关税水平和关税政策的不确定性,来提高消费者的福利和企业出口质量。

Impact of Tariff on Firm's Trade Margin Heterogeneity Based on Tariff Rate and Trade Policy Uncertainty Perspective

Tariff is an important factor that influences a firm's export decision-making.Using China's WTO accession as a quasi-natural experiment,based on the Chinese firms'matched data in both China Industrial Enterprise Database and Customs Trade Database during the years from 2000 to 2006,we empirically adopt the difference-in-difference method to investigate the heterogeneous impacts on the firms'trade margin from the two dimensions including tariff rates and trade policy uncertainty.The research finds that the reduction of tariff rates mainly increases a firm's extensive margin but the reduction of trade policy uncertainty mainly reduces a firm's intensive margin.Specifically speaking,the enterprises in the industry where the tariff rates drop more have an increase in their extensive margin,but the corresponding enterprises'intensive margin increases less,resulting in a decrease in their total export.In the industries where the tariff policy uncertainty reduces a lot,the intensive margin increases in the enterprises in the export to the United States while the corresponding extensive margin increase is relatively small,resulting in an increase in their total export to the United States.The research conclusion shows that government should reduce the tariff rates and tariff policy uncertainty to improve the consumer's welfare and the quality of firms'export.