National environmental monitoring and local enforcement strategies

Monitoring technologies are widely used by upper-level government to enhance local compliance and achieve better environmental quality. Given their limited spatial accessibility of monitoring, how these technologies shape local enforcement strategies is uncertain. Here we show the impact that the nationwide establishment of air-quality-monitoring stations in Chinese cities had on local pollution reduction, enforcement and social welfare. Leveraging high-resolution datasets and a quasi-experimental design, we found that the newly introduced monitoring stations led to an 8.03% reduction in PM2.5 concentrations in urban areas. Within these areas, there was a 0.57% greater reduction in PM2.5 concentrations in technically accessible areas than in non-accessible areas. The reduction in air pollution was associated with a decline in industrial activities and change in land use. A back-of-the-envelope estimation shows nontrivial urban spatial inequalities in welfare consequences. Our findings suggest that the application of monitoring technologies should take environmental justice into consideration for a more comprehensive approach to sustainable development. This study analyzes the impact of 1,436 air-quality-monitoring stations in Chinese cities. It found that these stations led to an 8.03% reduction in PM2.5 concentrations in urban areas. Within these areas, they resulted in 0.57% more reduction in PM2.5 concentrations in technically accessible areas compared to non-accessible areas, which also experienced an increase in housing prices and a decrease in air-quality-induced mortality.