Daylight Saving Time and Automobile Accidents: Evidence From Chile

Abstract

Under the evidence that the Daylight Saving Time (DST) regime does not accomplish its primary goal of saving energy, I analyze one of the main side effects, automobile accidents in Chile between 2002 and 2018. I use a Regression Discontinuity Design (RDD) exploiting the discrete nature of the transition into DST and a Difference-in-Difference (DID) approach, taking advantage of the changes in dates that the policy starts and ends over the years. I find a 2.7% reduction in automobile accidents under the DST regime. I isolate the two main mechanisms: sleep disruption and the reallocation of light. I find suggestive evidence that the sleep disruption effect plays a relevant role at both transitions: it increases automobile accidents by 6% the first week following the transition into DST and decreases them by 3.9% the first week following the transition into Standard Time (ST). I also find evidence that ambient light reduces serious and fatal accident risk.