长三角扩容对污染减排的空间分异特征及其机制

 基于长三角扩容的准自然实验,选取2008-2017年的211个地级市面板数据,运用双重差分法分析了长三角扩容后相关城市污染排放的影响及其内在机制,同时采用PSM-DID估计、平行趋势检验、合成控制法、安慰剂法等方法对结果进行稳健性检验。研究表明：长三角扩容对污染排放的显著负向作用发生在整体及原位城市,且原位城市的显著负向作用大于整体城市,但新进城市负向作用不显著;内在机制方面,长三角扩容后在规模效应、技术效应及结构效应的作用下,显著降低了长三角整体城市的污染排放,但扩容后新进城市的污染排放量因时间滞后性还未显著减少。因此,城市群应进一步强化区域一体化发展,创新区域环境污染治理协同机制,实现区域经济发展和环境保护“双赢”。

Spatial differentiation of the Yangtze River delta capacity expansion on pollution reduction and its mechanism

In a quasi-natural experiment of the expansion of the Yangtze River Delta, the panel data of 211 cities in China from 2008 to 2017 are analyzed. The difference-in-difference method is adopted to analyze the influence and the internal mechanism of the pollution emissions in related cities after the expansion of the Yangtze River Delta. The PSM-DID estimation, the parallel trend test, the synthetic control methods and the placebo test are adopted for the robustness test. It is shown that the expansion of the Yangtze River Delta would significantly reduce the pollution emissions in all related cities and the incumbent cities, but the reduction in the incumbent cities is greater than that in all related cities. The reduction of the emissions of the pollution is not significant in the new cities. In terms of the influencing mechanism, the pollution emissions in the whole Yangtze River Delta are significantly reduced through the scale effect, the technology effect and the structure effect, while the reduction of the pollution emissions is not so significant in the new cities due to the time delay. Therefore, it is necessary to strengthen the integrated regional development for the urban agglomeration and enhance the cooperation mechanism of the environmental pollution control in innovative regions, so as to realize the"win-win"goal-the regional economic development and the environmental protection improvement.