The role of digital infrastructure in reducing air pollution

Air quality enhancement reflects rising demands for a higher living standard while advancing green development. This study explores the impact of digital infrastructure on air pollution from a policy perspective, utilizing the Broadband China Strategy (BCS) as a quasi-natural experiment. Utilizing panel data from 283 Chinese cities from 2011 to 2019, this study employs a difference-in-differences model (DID) over multiple periods to evaluate the effects on air pollution of BCS and employs a double machine learning (DML) method for a robustness test. The results show that BCS has a significant suppressive effect on air pollution intensity. Mechanism analysis reveals that this reduction is achieved through a decrease in energy intensity. The influence of BCS on air pollution is particularly stronger in resource-based cities, large cities, and regions with relatively lax environmental regulations. Furthermore, we also find that the policy impact exhibits a significant mitigating effect on air pollution in cities within a 150–250 km radius. Overall, the study highlights the pioneering role of digital infrastructure in environmental governance and provides a theoretical foundation for differentiated governance and collaborative regional air pollution control in the digital era.