The unequal impact of natural light on crime

This paper studies the relationship between ambient light and criminal activity. I develop a Becker-style crime model that shows that a sudden increase in ambient light produces a larger reduction in crime in areas with less public lighting. Daylight savings time (DST), the natural experiment used, induces a sharp increase in natural light during crime-intense hours. Using geolocated data on crime and public lighting for the city of Montevideo in Uruguay, regression discontinuity estimates identify a strong and statistically significant decrease in robbery of 17%. The decrease is larger in poorly lit areas. Computing the level of public lighting at which DST has no effect on crime reduction, I identify the minimum level of public lighting that an area should target.