Michael Greenstone, Guojun He, Ruixue Jia, Tong Liu

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 increased by 35% immediately post–automation and were sustained. City-level variation in underreporting is negatively correlated with income per capita and positively correlated with true pre-automation PM10 concentrations. Further, automation’s introduction increased online searches for face masks and air filters, suggesting that the biased and imperfect pre-automation information imposed welfare costs by leading to suboptimal purchases of protective goods.

Areas of Focus: Environment
Definition
Environment
Producing and using energy damages people’s health and the environment. EPIC research is quantifying the social costs of energy choices and uncovering policies that help protect health while facilitating growth.
Air Pollution
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Air Pollution
Air pollution from fossil fuel combustion poses a grave threat to human health worldwide. EPIC research is using real-world data to calculate the effects of air pollution on human health...
EPIC-China
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EPIC-China
China is indisputably critical to addressing the global energy challenge. China is one of the world’s biggest economies, its top carbon emitter, and among its most polluted countries. Yet, China...