Research Seminar in Economics

June 24, 2026

Wildfires produce large amounts of air pollution via smoke, which can travel far beyond the original fire location. This paper studies the causal effect of wildfire smoke exposure on mortality in Mexico. I merge satellite image data on wildfire smoke plumes with administrative records and leverage high-frequency variation in smoke exposure within municipalities over time. I show that wildfire smoke over a municipality increases PM2.5 air pollution by 11%. At the same time, among those 60 years and older, mortality increases by 1.87 deaths per million on the day of smoke, and by an additional 1.69 deaths per million over the next three days. The mortality effect on short-term mortality in Mexico is high compared to prior studies in more developed countries and within Mexico, the effects are larger for individuals in poorer municipalities. I also study the effect of smoke induced air pollution on infant health. While I find some evidence of adverse effects from wildfire smoke on birth outcomes, overall effect sizes are small. According to my estimates, even long periods of wildfire smoke exposure during pregnancy reduce gestational age by less than a day, on average, though there is some evidence of adverse effects on respiratory health at birth.