区域一体化的减霾效应——基于断点回归的经验证据

Effects of regional integration on haze reduction: evidence from geographical regression discontinuity

大气污染的流动性以及治理过程中存在的搭便车现象决定了大气污染治理需要在更大的区域范围内实施联防联控政策。随着中国经济发展由高速增长转向高质量发展,经济发展的空间结构正在发生深刻变化,以城市群、都市圈为单位的区域一体化在推动经济发展以及环境治理过程中扮演着越来越重要的角色。文章采用2005-2019年中国区县面板数据,基于地理断点回归方法,研究以城市群为单位的区域一体化是否有利于更好地减霾。实证结果发现:(1)整体而言,以城市群为单位的区域一体化发挥了减霾效应,城市群边界内区县的PM_(2.5)年平均浓度相较城市群边界外区县低11.204μg/m^(3)。(2)机制研究表明,结构性减霾和技术性减霾是区域一体化发挥减霾效应的重要途径。前者主要通过中心区域与外围区域的产业分工和转移实现,后者主要通过中心-外围结构下技术转移和知识溢出实现。(3)区域一体化产生的减霾效应存在较大区域差异,发育较为成熟的三大城市群减霾效应最为显著。进一步地,以城市群为单位的大气污染联防联控政策起到了更好的减霾效果。(4)文章研究结论表明,区域一体化产生了显著的正环境影响,在城市群范围内持续构建区域间环境协同治理机制具有重要的现实意义。应积极推进在更大空间尺度统筹治理大气污染,重视区域一体化过程中不同区域间产业的分工和协作,同时加大区域内技术创新投入,鼓励地方、企业进行污染治理技术及减排技术研发。

The mobility of air pollution and the free-riding phenomenon in the process of pollution control determine that joint prevention and control policies should be implemented in a larger area. As China’s economic development shifts from high-speed growth to high-quality development, the spatial structure of economic development is undergoing profound changes. Regional integration with urban agglomerations and megalopolis as units plays an increasingly important role in promoting economic development and environmental governance. Based on the regression method of geographical regression discontinuity, this study used the panel data of prefectures and counties in China from 2005 to 2019 to study whether the regional integration of urban agglomeration was conducive to better haze reduction. The empirical results showed that:(1) On the whole, the regional integration of urban agglomeration played a role in haze reduction, and the annual average PM_(2.5) concentration of prefectures and counties within the urban agglomeration was 11.204 μg/m^(3) lower than that of those outside the urban agglomeration.(2) Mechanism analysis showed that structural haze reduction and technical haze reduction were important ways for regional integration to exert haze reduction effects. The former was mainly realized through industrial division and transfer between the central area and the peripheral area, and the latter was mainly realized through technology transfer and knowledge spillover under the center-periphery structure.(3) The haze reduction effects produced by regional integration had large regional differences, and the three major urban agglomerations with relatively mature development had the most significant haze reduction effects. Furthermore, the joint prevention and control policy of air pollution with urban agglomeration as the unit exerted a better effect on haze reduction.(4) The implication of this paper showed that: regional integration has produced a significant positive environmental impact and it is of great practical significance to continuously build an inter-regional environmental collaborative governance mechanism within the scope of urban agglomeration. It is necessary to actively promote the overall control of air pollution on a larger geographical scale and pay attention to the division of labor and cooperation between industries in different regions in the process of regional integration, and at the same time, increase investment in technological innovation within the region and encourage local government and enterprises to carry out research and development of pollution control and emission reduction technologies.