Smarter Cities, Fairer Emissions? Evidence from Smart City Pilot Policy and Urban Carbon Inequality

The Smart City Pilot (SCP) policy has emerged as an important initiative for promoting technological innovation and sustainable development. However, its impact on environmental equity, particularly concerning inter-urban carbon inequality, remains underexplored. Drawing on 2008–2021 panel data from 281 Chinese prefecture-level cities, this research investigates the impact of SCP policy on urban carbon inequality. To determine causality, we employ a staggered Difference-in-Differences (DID) approach. The results reveal that this initiative substantially reduces inter-city carbon inequality, a result that remains stable across various robustness tests. Mechanism tests indicate that this effect operates through the advancement of artificial intelligence, the expansion of new digital infrastructure, and the transformation of government intervention. Furthermore, heterogeneity analysis reveals that the effect is stronger in western regions, resource-based cities, and high-sprawl cities, as well as in regions with lower marketization and weaker environmental regulations. These findings underscore the role of SCP policy not only in advancing low-carbon development but also in promoting carbon equality.