绿色高铁：高铁开通能降低雾霾污染吗？

Green High-Speed Railway:Does High-Speed Railway Reduce Haze Pollution?

近年来中国高铁迅猛发展,对经济、结构、技术等方面产生日益显著的影响,这进一步影响到雾霾污染,因此亟待检验高铁开通的雾霾污染效应。基于2003-2016年中国285个城市的面板数据,本文利用高铁在不同城市、开通时间上的变异,使用渐进性的双重差分方法估计了高铁开通对雾霾污染的影响。研究发现,相比于未开通城市,高铁开通城市的PM2.5地表浓度平均降低1.81%,意味着高铁开通带来了环境红利;从动态效应上看,高铁开通的减霾效应出现在开通后的第一年和第二年。同时,高铁开通对雾霾污染的影响存在异质性,减霾效应在东中部城市、沿海城市、非资源型城市以及高创新水平城市、高人力资本水平城市更加显著。机制分析表明,高铁开通通过规模效应、结构效应和技术效应三条途径影响雾霾污染水平。本文丰富了高铁与雾霾污染的相关文献,从雾霾污染的视角为高铁建设的经济社会效益评估提供了环境方面的证据。

In recent years,the rapid development of China\s high-speed railway has an increasingly significant impact on the economy,structure,technology and so on,which further affects haze pollution.Therefore,it is urgent to examine the effect of high-speed railway on haze pollution.Using the opening of the high-speed railway as a quasi-natural experiment,this paper investigates the causal impact of high-speed railway on haze pollution,based on the panel dataset of 285 prefecture-level cities in China from 2003 to 2016 and the method of the difference-in-differences(DID)model.The empirical results show that PM2.5 concentration of the treated cities is 1.81%lower than the control cities.That\s to say,the opening of high-speed railway has brought environmental dividends.From the perspective of dynamic effects,the haze reduction effect appears between the first year and the second year after the opening of the high-speed railway.Meanwhile,the impact of high-speed railway on haze pollution is heterogeneous.Specifically,the haze reduction effect is more significant in the samples of eastern and central cities,coastal cities,non-resource cities,cities with high innovation and cities with high human capital.In addition,the mechanism analysis shows that high-speed railway reduces haze pollution by scale effect,structure effect and technology effect.In terms of environmental welfare,the total value of statistical lives saved due to the haze reduction effect of high-speed railway in the sample period is about 970 million in 1997 CNY.This paper enriches the relevant literature on high-speed railway and haze pollution,and provides environmental evidence for the economic and social benefit evaluation of high-speed railway construction from the perspective of haze pollution.