The Influence of Digital Infrastructure on Carbon Emission Intensity: Evidence from the Broadband China Policy

With accelerating global warming, reducing carbon emissions has emerged as a core task of global climate governance. In this process, digital infrastructure acts as a crucial catalyst for achieving sustainability goals. Drawing on a panel dataset covering 287 Chinese prefecture-level cities between 2010 and 2023, this paper examines how Broadband China policy influences carbon dioxide (CO2) emission intensity via a difference-in-differences approach. The outcomes show that Broadband China policy significantly reduces CO2 emission intensity, with pilot cities exhibiting a 5.01% decrease relative to non-pilot cities. This effect operates primarily through promoting green technological innovation and reducing energy consumption intensity. The reduction is more pronounced in large-scale and high developed regions, whereas the effect remains limited in small-scale and less developed regions. This study contributes to the literature by using carbon emission intensity, a structural indicator that better reflects the efficiency of low-carbon transition, to examine the digital economy and environmental governance. It further provides empirical support for other developing countries seeking to advance emission reduction through digitalization.