中国低碳城市试点政策扩散模式及减污效应

Diffusion model and air pollution control effect of low-carbon city pilot in China

低碳试点政策是实现双碳目标的一项重要制度安排,然而不同扩散模式下的低碳试点政策对改善环境质量的政策效果差异尚不明确。基于2003—2019年中国281个地级市的面板数据,将3批低碳试点政策视为准自然实验,采用渐进双重差分模型评估不同扩散模式下的低碳试点政策对改善环境质量的差异化影响效应。研究发现:第一,低碳城市建设显著降低了空气污染水平,有助于改善环境质量;第二,层级扩散模式下的低碳试点政策减污效应优于主动扩散模式;第三,层级扩散与主动扩散模式下的低碳试点政策对提升环境质量的影响效应在不同经济发展水平、不同类型的城市中表现出较为明显的异质性。研究结果为深入打好污染防治攻坚战、建设人与自然和谐共生的美丽中国提供了有益的政策启示。

Low-carbon city pilot is an important institutional arrangement to achieve the goals of carbon peaking and carbon neutrality.However,the policy effect of low-carbon city pilot policies under different diffusion modes on improving environmental quality is not clear.Based on the panel data of 281 prefecture-level cities in China from 2003 to 2019,this study regards the three batches of low-carbon city pilots as quasi-natural experiments,and uses the time-varying DID method to evaluate the differential effects of low-carbon city pilot policies on improving environmental quality under different difusion modes.The results show that(1)The construction of low-carbon city pilot significantly reduces the air pollution level and contributes to the improvement of environmental quality.(2)The air pollution control effect of low-carbon city pilot under hierarchical diffusion mode is better than that under active diffusion mode.(3)The effects of low-carbon city pilot under hierarchical and active diffusion modes on improving environmental quality show obvious heterogeneity among different levels of economic development and different types of cities.This study provides useful policy implications for further fighting the battle of pollution prevention and control and building a beautiful China with harmonious coexistence between man and nature.