Zhang Qingyong, Mao Xianqiang, Wang Zhengzao, Tan Yutong, Zhang Ziyin, Wu Yanjie, Gao Yubing
School of Environment, Beijing Normal University, Beijing 100875, China.
School of Economics and Management, Beijing University of Technology, Beijing 100124, China.
Environ Sci Policy. 2023 Jul;145:50-59. doi: 10.1016/j.envsci.2023.04.009. Epub 2023 Apr 6.
The emergency response to the COVID-19 pandemic had an extreme exogenous impact on society and the economy. This paper aims to explore the impacts of the national emergency response and the subsequent emergency response termination on air quality and its policy implications through regression discontinuity design (RDD) estimation by employing panel data on daily air quality from January 1, 2019, to July 31, 2020, for 290 cities in China. The empirical results showed that the emergency response resulted in a significant decrease in most of the major pollutant concentrations within a short time frame, and the average air quality index (AQI) decreased by approximately 11.0%. The concentrations of PM, PM, SO, NO, and CO decreased by approximately 18.8%, 13.1%, 13.5%, 11.1% and 6.7%, respectively, while the O concentration did not change significantly. Further causal analysis found that mandatory traffic restrictions and the shutdown of industries were two important factors that contributed greatly to air quality improvement. Moreover, since the process of returning to normal daily activities and promoting the economy were gradual, the results showed that air pollution did not rebound immediately after the government called for the "resumption of production and work" and announced the "termination of the emergency response". Our findings suggest that to achieve a substantial and sustainable improvement in air quality, it is necessary to continuously implement strict emission control routines and take co-control measures for various VOCs precursors of ozone.
对新冠疫情的应急响应给社会和经济带来了极端的外部冲击。本文旨在通过回归断点设计（RDD）估计，利用2019年1月1日至2020年7月31日中国290个城市的每日空气质量面板数据，探讨国家应急响应及其随后的应急响应终止对空气质量的影响及其政策含义。实证结果表明，应急响应在短时间内导致大多数主要污染物浓度显著下降，平均空气质量指数（AQI）下降了约11.0%。PM、PM、SO、NO和CO的浓度分别下降了约18.8%、13.1%、13.5%、11.1%和6.7%，而O浓度没有显著变化。进一步的因果分析发现，强制性交通限制和工业停产是空气质量改善的两个重要因素。此外，由于恢复日常活动和促进经济的过程是渐进的，结果表明，在政府呼吁“复工复产”并宣布“应急响应终止”后，空气污染并没有立即反弹。我们的研究结果表明，要实现空气质量的实质性和可持续改善，有必要持续实施严格的排放控制措施，并对臭氧的各种挥发性有机物前体采取协同控制措施。
