We examine the introduction of automatic air pollution monitoring, which is a central feature of China’s “war on pollution.” Exploiting 654 regression discontinuity designs based on city-level variation in the day that monitoring was automated, we find that reported PM10 concentrations...

We examine the introduction of automatic air pollution monitoring, which is a central feature of China's "war on pollution." Exploiting 654 regression discontinuity designs based on city-level variation in the day that monitoring was automated, we find that <i>reported</i> PM₁₀ concentrations increased...