Population size heterogeneity.

The market-oriented reform of China’s power market has gradually transformed power prices from government pricing to market regulation, which not only promotes the production efficiency of industrial enterprises, but also inhibits the excessive consumption and waste of power by residential power users. This paper uses the data from 2006–2018 combined with the precious industrial power price data and macroeconomic data of 100 cities in China, takes the marketization reform of the power market in 2015 as a quasi-natural experiment, and uses the difference-in-differences model to empirically study the causal relationship between power market reform and air pollution for the first time. The study found that power market reform can reduce air pollution, and this conclusion is also supported by a number of robustness tests. Mechanism analysis shows that power market reform can reduce air pollution by improving power market efficiency, promoting technological progress, and reducing power consumption. Heterogeneity analysis shows that power market reform can suppress air pollution more significantly in eastern regions, regions with severe air pollution, and regions with larger populations. This paper not only provides new research perspectives and research ideas for air pollution prevention and control, but also provides empirical evidence for the positive externalities of power market reform.中国电力市场的市场化改革已逐步推动电价从政府定价转向市场调节，此举既提升了工业企业的生产效率，也抑制了居民用电用户的过度用电与电力浪费。本文采用2006—2018年的相关数据，结合中国100座城市的珍贵工业电价数据与宏观经济数据，以2015年电力市场市场化改革为准自然实验（quasi-natural experiment），首次运用双重差分模型（Difference-in-Differences）实证探究电力市场化改革与大气污染之间的因果关系。研究发现，电力市场化改革能够降低大气污染水平，该结论亦得到多项稳健性检验（robustness tests）的支持。机制分析表明，电力市场化改革可通过提升电力市场运行效率、推动技术进步以及降低电力消耗三条路径缓解大气污染。异质性分析（Heterogeneity analysis）显示，电力市场化改革对大气污染的抑制效应在东部地区、大气污染较重地区以及人口规模较大的地区更为显著。本文不仅为大气污染防治工作提供了全新的研究视角与思路，也为电力市场化改革的正外部性（positive externalities）提供了实证依据。