We leverage the timing of coalmine accidents to examine the effect of coal mining on air
pollution. Safety regulations mandate that coal mining be suspended if a mine experiences
an accident with 10 or more fatalities. We use a stacked difference-in-differences approach
to compare counties with an accident to those experiencing an accident more than two years
earlier or later. We provide evidence that the timing of accidents cannot be predicted. Next,
we combine satellite-based air pollution data at the county-day level with the dates of …