流域跨界污染治理的环境政策效应研究

On Effects of Environmental Policy on Transboundary Watershed Pollution Control

近年来,以河长制为代表的垂直型环境治理政策初步改善了属地内水污染问题,但流域跨界污染仍然是当前中国最突出的环保问题之一。本文基于因果推断分析框架,以河长制和横向生态补偿两种政策的实施为准自然实验,利用三重差分法(DDD)深入考察了水污染密集型产业空间转移的动态及成因。研究发现:我国存在严重的水污染边界效应,而河长制的实施一定程度上抑制了水污染密集型企业的向上迁移,且在引入横向生态补偿机制后,其对流域跨界污染现象的治理效果更加显著。其作用机制在于,横向生态补偿政策通过引入市场机制实现对各级河长的激励和约束,削弱了上下游地方政府在环境规制方面的逐底竞争,抑制了其牺牲环境换取经济增长的动机,有利于推动区域间协同治理。进一步研究发现,上述水环境治理政策在经济发展水平较高、减排压力更大的地区表现出更好的政策效果。

In recent years,the vertical environmental governance policies represented by the river chief system have initially improved the water pollution issues.However,transboundary pollution in watersheds remains one of the most prominent environmental problems in China.Based on the causal inference analysis framework,this paper used the implementation of river chief system and horizontal ecological compensation as quasi-natural experiments,and used difference-in-differences-in-differences(DDD)method to investigate the dynamic trends and causes of the spatial transfer of water pollution-intensive industries.The research showed that there was a serious boundary effect of water pollution in China,with the implementation of river chief system inhibiting the upward migration of water pollution-intensive enterprises to some extent.Moreover,after the introduction of horizontal ecological compensation mechanism,the effect of river chief system on transboundary pollution in river basins was more remarkable.The mechanism underlying this effect was that of the horizontal ecological compensation policy provided incentives and constrains for river chiefs at all levels by introducing market mechanism.This approach weakened the bottom-level compensation among local governments regarding environmental regulation,and inhibited their motivation of sacrificing the environment for economic growth,thus promoting coordinated governance among regions.Further research indicated that the above-mentioned policies showed better policy effectiveness in regions with higher levels of economic development and greater pressure on emissions reduction.