关键词: 贸易政策不确定性,利润变化,边际效应,中介效应

Abstract: The profit of export enterprises is easily affected by the trade policy environment. This paper uses the data of Chinese micro enterprises from 2000 to 2006 to conduct an empirical study of the short-term and long-term influences of the trade policy uncertainty on the profit levels of the export enterprises. The findings show that, whether in the short-term or in the long-term, the decrease of trade policy uncertainty can significantly promote the profitability of the export enterprises, trade openness is an important intermediary transmission mechanism. Specifically, the effect of trade policy uncertainty on the profit rate of the export enterprises follows the law of marginal evolution in the spatial distribution; while in the time dimension, the effect of trade policy uncertainty on the net profit growth rate of the export enterprises is mainly realized through the channel of “improving profit creation.”

Key words: trade policy uncertainty; profit change; marginal effect; intermediary effect