Massive wildlife losses over the past 50 years have brought new urgency to identifying both the drivers of population decline and potential solutions. We provide the first large-scale evidence that air pollution, specifically ozone, is associated with declines in bird abundance in the United...

Efficient pollution regulation equalizes marginal abatement costs across sources. Here we study a new flaring regulation in North Dakota's oil and gas industry and document its efficiency. Exploiting detailed well-level data, we find that the regulation reduced flaring 4 to 7 percentage points...

We leverage a natural experiment, where a large national automotive racing organization switched from leaded to unleaded fuel, to study how ambient lead exposure and nutrition impact learning in elementary school. This provides quasi-experimental evidence linking measured quantities of lead...