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WestEd’s Jonathan Nakamoto and Trent Baskerville summarized this study conducted by researchers Jennifer L. Doleac and Nicholas J. Sanders to investigate the impact of increased daylight during evening hours due to Daylight Savings Time (DST) on criminal activity.

Using a retrospective Regression Discontinuity Design (RDD) study, the researchers used crime and population data from 558 jurisdictions in the United States between 2005 and 2008. They found that DST led to reductions in robbery and rape rates, with the most significant decreases occurring in the hour following sunset.

The study revealed statistically significant reductions of 7 percent for robbery and 11 percent for rape in daily crime rates after DST, while there were no significant changes for aggravated assault and murder. However, analysis of crime rates specifically within the hour after sunset revealed larger reductions of 27 percent for robbery and 38 percent for rape. Importantly, the findings indicated that criminal activity was not shifted to other times of the day. The authors estimated that these reductions could result in annual savings of nearly $60 million due to avoided robberies and approximately $250 million due to avoided rapes as a result of DST implementation.