数字基础设施如何影响城市碳排放强度?——基于“宽带中国”战略的准自然实验

How Does Digital Infrastructure Affect Urban Carbon Intensity?:A Quasi-Natural Experiment Based on the“Broadband China”Strategy

在数字经济时代,完善数字基础设施建设是实现减排战略目标的重要手段。选取我国2007—2019年285个城市的面板数据,采用渐进双重差分模型探讨了数字基础设施建设对城市碳排放强度的影响。研究发现,“宽带中国”战略显著降低了城市碳排放强度,在排除可能的非随机选择因素和内生问题后,这一结论仍然有效。异质性分析表明,“宽带中国”战略对碳排放强度的影响具有区位异质性、城市规模异质性和资源禀赋异质性。机制分析表明,城市绿色创新能力和外商直接投资是“宽带中国”战略抑制碳排放强度的重要机制。空间视角下,“宽带中国”战略对碳排放强度具有空间溢出效应,且在不同权重矩阵下有所差异。

In the era of digital economy,improving the construction of digital infrastructure is an important means to realize the goal of emission reduction strategy.In this paper,we select the panel data of 285 cities in China from 2007 to 2019,and use the asymptotic difference-in-difference model to explore the impact of digital infrastructure construction on urban carbon emission intensity.It is found that the“Broadband China”strategy significantly reduces urban carbon emission intensity,and this conclusion remains valid after excluding possible non-random selection factors and endogenous problems.Heterogeneity analysis shows that the impact of the“Broadband China”strategy on carbon emission intensity is characterized by location heterogeneity,urban scale heterogeneity and resource endowment heterogeneity.The mechanism analysis shows that the urban green innovation capacity and foreign direct investment are important mechanisms for the“Broadband China”strategy to curb carbon emission intensity.From the spatial perspective,the“Broadband China”strategy has spatial spillover effects on carbon emission intensity,which varies under different weight matrices.