Air quality and risky behaviors on roads

This paper provides the first evidence showing that air pollution can reduce life-threatening risky behaviors. We study the impact of air pollution on traffic accidents caused by risky driving behaviors, using the universe of accident records and high-resolution air quality data of Taiwan from 2009 to 2015. We find that air pollution significantly decreases accidents with casualties caused by driver violations, and that this effect is nonlinear. In addition, such negative effects are only observed in time when road users can visually assess air pollution levels, suggesting that air quality primarily reduces road users' risky behaviors through visual channels rather than through the respiratory system.