中国城市数字经济发展对环境污染的影响及机理研究

Research on the Impact of Urban Digital Economy Development on Environmental Pollution and Its Mechanism

数字经济为政府治理、企业生产和居民生活等领域带来了深刻变革,数字经济发展是否抑制了环境污染是亟需解答的问题。文章基于中国285个城市2011-2018年的面板数据,运用固定效应模型、空间杜宾模型、中介效应模型等方法,多维度实证检验了数字经济发展对城市环境污染的影响及其中介机制。研究发现,数字经济发展显著降低了城市各类环境污染物的排放,运用工具变量估计、引入外生政策冲击、替换解释变量等方法进行稳健性检验后,该结论仍然成立。数字经济发展对不同污染物的降低作用有所差异,对工业二氧化硫排放量的降低效应最明显,工业废水和工业烟尘排放量次之,对PM_(2.5)浓度的降低效应最小。中介效应分析表明,绿色创新和产业结构优化是数字经济降低城市环境污染物排放的重要机制。空间溢出效应分析表明,数字经济发展对周边城市各类环境污染物存在负向空间溢出效应。空间异质性分析表明,东部地区数字经济发展的污染减排效应相比中、西部地区更大,且数字经济发展仅在东、中部地区具有显著的空间溢出效应。文章的内容丰富了有关环境污染影响因素的研究,也是对有关数字经济研究的有效补充,研究结论为数字经济助力环境污染治理提供了可靠的实证依据,同时为发展数字经济、充分发挥数字经济的污染减排提供了政策参考。

China's digital economy has developed rapidly over the past decade,and it has been gradually integrating and infiltrating into various fields of government governance,enterprise production and residents' life.The economy and society are undergoing profound changes.In this context,can the development of digital economy improve resource utilization efficiency and promote pollutants emissions reduction?If so,what is the path and mechanism of this impact?The discussion of the above problems is not only conducive to enrich the research content of digital economy,but also has practical significance for promoting the improvement of ecological environment and realizing high-quality economic development.Based on the panel data of 285 cities in China from 2011 to 2018,this study empirically tests the impact of digital economy development on urban environmental pollutants and its intermediarymechanism by using fixed effect model(FE),spatial durbin model(SDM),mediation effect model(ME),difference-in-difference model(DID)and instrumental variable analysis(IV).The empirical results show that the development of digital economy has significantly reduced the emissions of various urban environmental pollutants.After the robustness test by using instrumental variable,introducing exogenous policy impact and replacing explanatory variables,this conclusion is still valid.The development of digital economy has different effects on the reduction of different pollutants.The reduction effect on industrial sulfur dioxide emissions is the most obvious,followed by industrial wastewater and industrial smoke emissions,and the reduction effect on PM_(2.5) concentration is the least.The mediating effect analysis shows that the development of digital economy has significantly promoted the increase of the number and quality of green patents,and promoted the emissions reduction of pollutants through green innovation effect.In addition,the development of digital economy has significantly improved the level of upgrading and rationalization of industrial structure,and promoted pollutants emission reduction through the effect of industrial structure optimization.The analysis of spatial spillover effect shows that the development of digital economy has a negative spatial spillover effect on various pollutants in surrounding cities.Spatial heterogeneity analysis shows that the pollutants reduction effect of digital economy development in the eastern region is greater than that in the central and western regions,and digital economy development has significant spatial spillover effect only in the eastern and central regions.The possible contributions of this study are as follows.Firstly,this paper makes a beneficial discussion on the pollutants reduction effect of the development of digital economy from both theoretical and empirical perspectives,enriches the research on the influencing factors of environmental pollution,and is also an effective supplement to the research on digital economy.Secondly,this paper discusses the mechanism of the impact of digital economy development on environmental pollution theoretically and empirically,combined with heterogeneity analysis,and tries to deconstruct the internal logical relationship between them.Thirdly,the“Bartik instrument”method and the DID method with"Broadband China"pilot policy as the exogenous impact are used to better solve the endogenous problem and ensure the robustness of the conclusion,thus provide a more reliable empirical reference for digital economy to contribute to environmental pollution control.The results of this paper provides a policy reference for developing digital economy and giving full play to the pollutants reduction effect of digital economy.