Digital Economy and Urban Carbon Emissions: A Quasi-Natural Experiment of the National Big Data Comprehensive Pilot Zone in China
利用2006-2019年中国168个地级市面板数据，通过双重差分法评估国家大数据综合试验区政策对城市碳排放的影响，发现该政策通过提升能源效率、绿色全要素生产率和促进高技术产业集聚显著降低碳排放，且存在空间溢出效应。
In this study, we assess the impact of digital economy development on urban carbon emissions using a difference-in-differences (DID) approach based on the quasi-natural experiment of the national big data comprehensive pilot zone (NBDCPZ) policy and panel data from 168 prefecture-level cities in China from 2006 to 2019. We find that the establishment of NBDCPZ has a significant carbon emission reduction effect. This finding is robust to various sensitivity tests. Further mechanism validation illustrates that the construction of NBDCPZ promotes the regional digital development level and reduces urban carbon emissions through three channels: improving energy efficiency to optimize energy consumption, increasing green total factor productivity, and promoting the clustering of high-tech industries. The heterogeneity analysis concludes that the carbon emission reduction effect of NBDCPZ policy varies with different regional locations and different city characteristics. Moreover, using spatial models, we find that the positive impact is characterized by spatial spillover effect. The findings provide detailed empirical evidence to formulate urban development strategies for enabling carbon reduction of the digital economy.