贸易自由化与进口中间品质量升级——来自中国海关产品层面的证据

Trade Liberalization and Quality Upgrading of Intermediate Inputs:Evidence from Chinese Customs Data

本文通过使用2000—2005年间我国高度细化的海关全样本进口数据,探讨了贸易自由化对于进口中间产品的质量的提升作用。为了准确地将质量从进口品价格信息中分离出来,我们运用了Khandelwal(2010)的模型估计了来自203个国家的3 714种进口中间品的质量。我们首先发现:产品异质性程度越高时、质量梯度越长,质量到价格的对应更加明显:质量越高,价格越低。但当质量梯度变短、产品同质性程度越高时,价格并不是质量的很好的度量指标。由于中间品质量的提升可能受到最终产品关税减免的影响,我们利用中国进口中间品关税豁免的特性,创新性地运用倍差法,选择受到关税免除保护的加工贸易为对照组。结果发现,相对于加工贸易,贸易自由化显著提升了一般贸易中进口中间品质量。

Using highly disaggregated Chinese product-level trade data,this paper investigates the impact of trade liberalization on the quality of imported inputs within narrow product categories.We first follow Khandelwal（2010）＇s model to estimate quality of inputs imported to China.To estimate the impact of both input tariff reductions and output tariff reductions,we choose processing trade,which is free of both tariffs,as control group,and implement Difference-in-Difference method.The result confirms that trade liberalization promotes quality of imported inputs in ordinary trade relative to processing trade.