Digital Economy Development and Provincial Sulfur Dioxide Emissions in China: Multi-Dimensional Evidence, 2000–2022

Curbing industrial air pollution remains central to China’s sustainable transition under the dual-carbon commitment, and the digital economy has been proposed as an enabler of cleaner production. Yet most evidence centers on carbon emissions and single-dimensional digital measures, leaving the link between multi-dimensional digital development and sulfur dioxide (SO2) emissions underexplored. We construct a multi-dimensional digital economy index (DEI) from three county-aggregated digital integration sub-indicators using principal component analysis and assemble a balanced panel of thirty provinces over 2000–2022 (N = 690). Using two-way fixed-effects estimation with cluster-robust inference, we find that DEI is negatively associated with provincial SO2 emissions: a one-unit increase in DEI is associated with 19.2 percent lower emissions. The association survives wild cluster bootstrap inference, province-specific linear trends, alternative composite weights, two alternative SO2 measures, and a Bartik-style exposure–shock instrumental-variable sensitivity analysis. Integration-type dimensions carry the stronger effect. A formal mediation analysis shows that digital development lowers coal reliance and raises regulation and innovation. Yet no observable channel statistically mediates the total effect. This pattern is consistent with abatement operating through emissions monitoring and compliance. The findings position digital development as a correlate of air-quality improvement and inform digital infrastructure planning under the dual-carbon framework.