自由贸易试验区的环境效应及其作用机制

Environmental Effects and Mechanisms of Pilot Free Trade Zones

设立自由贸易试验区是中国构建开放型经济新体制的重大举措,但至今还没有文献对其环境效应进行科学的量化评估。本文以2005—2018年中国285个城市面板数据为研究样本,采用多期双重差分法系统考察设立自贸试验区对环境质量产生的政策净效应,并进一步分析其作用机制。研究发现:(1)自由贸易试验区的设立显著降低了环境污染程度,该结论在识别条件检验、工具变量法等一系列稳健性检验中依然成立;(2)自由贸易试验区的设立显著促进了所在城市经济规模扩大,通过规模效应降低了所在城市的环境污染程度;(3)自由贸易试验区的设立显著促进了所在城市产业结构升级,通过结构效应降低了所在城市的环境污染程度;(4)自由贸易试验区的设立显著促进了所在城市的技术进步,通过技术效应降低了所在城市的环境污染程度。

The establishment of pilot free trade zones is a major step taken by China to build a new system for an open economy,but there is no scientific and quantitative evaluation of its environmental effects.Based on the panel data of 285 cities in China from 2005 to 2018,this paper systematically investigates the net policy effect of setting up pilot free trade zones on environmental quality by using the multi-phase differential method,and further analyzes its mechanism.The results show that:firstly,the establishment of pilot free trade zones significantly improves environmental pollution,which is still true in a series of robust tests,such as identification condition test and instrumental variable method;secondly,the establishment of pilot free trade zones significantly promotes the expansion of the economic scale of the cities in which they are located,and improves the environmental pollution of the cities through the scale effect;thirdly,the establishment of pilot free trade zones significantly promotes the upgrading of industrial structure in the cities where they are located,and improves the environmental pollution of the cities through structural effects;finally,the establishment of pilot free trade zones significantly promotes the technological progress of the cities in which they are located,and improves the environmental pollution of the cities through the technological effect.