环保督察与空气质量改善:立足城市情境的效应异质性分析

作为生态环境保护领域的一项重大制度创新,中央环保督察已经成为党和政府推动生态文明建设的重要政策工具。然而,对于中央环保督察能否改善空气质量,尤其是其效果的可持续性,尚存在诸多争议。立足于匹配后的地级市数据评估中央环保督察对空气质量改善的平均效应,结果表明中央环保督察尽管在短期内显著改善了空气质量,其长期效应并不显著。然而,借助基于模型的递归分解法和随机森林法进一步发现:中央环保督察的长期效应存在显著的情境差异性:中央环保督察对于空气污染较重的城市具有长期改善效应,且东部城市尤为明显;一个城市的经济发展水平越高,中央环保督察效应越具有长效性;政府规模和财政自主性对中央环保督察效应起到截然相反的调节作用:前者的扩张会削弱长期效应,而后者的提升则会强化长期效应。揭示城市情境对督察效应的调节作用,有助于深化学界对中央环保督察长效性的条件认识,也为进一步完善该制度、提升其效能提供了重要的思路。

Can Central Environmental Protection Inspection Improve Air Quality?:A Context-Based Effect Heterogeneity Analysis

Central environmental protection inspection(CEPI)is a major institutional innovation in environmental governance that has become a key policy instrument to promote ecological civilization in 21st Century China.But not everyone agrees.The effectiveness of CEPI in improving air quality,especially its sustainability in the long run,is an open question.Based on matched city-level data,this study first evaluated the average impact of CEPI on air quality and found only short-term beneficial effects.After adopting model-based recursive partitioning tree and random forest approaches,this study observed the long-term impacts of CEPI on air quality are heterogeneous across cities.First,the long-term benefits of CEPI are more prominent in high-pollution and eastern cities.Second,the air cleaning impact of CEPI tends to be more sustainable in those cities with higher levels of economic development.Third,the moderating effects of government size and fiscal autonomy are contradictory;the former prohibits long-term effects while the latter plays a strengthening role.By revealing the contextual effects of CEPI on air quality,this paper provides a deeper understanding of the conditions that make central inspections more effective and persistent in reducing environmental pollution at the local level.