Digital economy and integrated pollution–carbon pressure: spatial spillovers and evidence from Chinese cities

Digital transformation is increasingly recognized as an important pathway toward urban sustainability. However, how digital economy development affects integrated pollution–carbon pressure across spatially connected cities remains insufficiently understood. Using a balanced panel dataset of 266 Chinese prefecture-level cities from 2010 to 2023, this study constructs an integrated pollution–carbon pressure index (IPCB) and employs a two-way fixed-effects Spatial Durbin Model to examine the environmental effects of digital economy development. The results show that digital economy development is significantly associated with lower IPCB, indicating that digital transformation contributes to alleviating the combined environmental pressure generated by conventional pollutants and carbon emissions. Spatial-effect decomposition further reveals significant negative direct, indirect, and total effects, suggesting that the environmental benefits of digitalization extend beyond local administrative boundaries through spatial spillovers. Exploratory subgroup analyses reveal differing coefficient patterns across regions, urban-agglomeration status, and city-size groups; because formal cross-group coefficient-equality tests are not conducted, these patterns are interpreted as exploratory rather than as statistically confirmed heterogeneity. Moreover, energy consumption intensity and artificial intelligence attention strengthen the negative association between digital economy development and IPCB, highlighting the importance of local conditions in translating digital transformation into environmental improvements. The main negative association is supported by alternative measurement and permutation-based placebo tests, while the sample-exclusion, lagged-variable, and policy-based checks reveal some variation in local and spillover estimates. These results emphasize the role of digital connectivity, targeted digital upgrading, and technology-related information diffusion in supporting sustainable urban development.