From information dissemination to environmental impact: the role of government microblogs in urban pollution mitigation

The rapid diffusion of digital communication platforms has transformed local environmental governance in China. This study examines how municipal environmental departments’ Weibo accounts function as institutionalised channels for disseminating environmental knowledge, policy signals, and enforcement information. Grounded in information asymmetry theory, it contends that digital tools bridge government-citizen-firm information gaps, aiding pollution mitigation. Using panel data for 287 cities from 2000–2023 and a staggered difference-in-differences design complemented by instrumental variables, mediation, and spatial models, the results show that the operation of environmental Weibo accounts significantly lowers urban PM2.5 concentrations. The effect occurs through three pathways: raising citizens’ environmental awareness, strengthening firms’ regulatory compliance, and increasing reputational exposure of polluters. Posts with policy documents, visual content, and higher interaction further amplify these effects. The study advances understanding of local digital governance by showing how government social media serve as informational infrastructures that shape behaviour and promote urban sustainability.