京津冀及周边大气污染联防联控政策实施效果评估——基于多期差分的实证研究

Evaluation on the Effects of Joint Prevention and Control of Air Pollution in Beijing-Tianjin-Hebei Region and Its Surrounding Areas——An Empirical Study Based on Multi-period Difference-in-Difference Model

以京津冀及周边地区为研究对象,针对不同城市实施联防联控政策的时间不同,运用多期双重差分模型构造一个准自然实验,评估联防联控政策实施效果,并考察政策的动态效果和异质性影响。研究发现,该政策使京津冀及周边地区空气质量整体改善了7%左右。一系列稳健性检验均表明基本结论的可靠性。动态来看,随着联防联控范围的扩大和政策的完善,空气质量改善的效果日趋明显。异质性方面,空气污染越严重的城市,在纳入大气污染联防联控范围后,其空气质量改善程度超过样本整体平均水平近一倍,达到14%左右。

Taking Beijing-Tianjin-Hebei region and its surrounding area as a case,this paper constructs a quasi-experimental design and applies a multi-period difference-in-difference model to examine the effects of regional joint prevention and control policies on air quality improvement and investigate its dynamic and heterogeneous effects.The study finds that the policy has improved the regional air quality by about 7%.A series of robustness tests prove the reliability of the basic results.From a dynamic point of view,as the scope of policy implementation has expanded and control measures have become increasingly strict,the effect of air quality improvement has become more significant.In terms of heterogeneity,cities with more serious air pollution have greater improvement in air quality after joining the joint regulation of air pollution,reaching about 14%.