What Do Bicycle Helmet Laws Do? Evidence From Canada

Twenty‐one states and the District of Columbia require youths to wear helmets when riding a bicycle, and there has been a push to extend such laws to adults. We provide new evidence on helmet laws by studying Canada using difference‐in‐differences models and restricted area‐identified public health survey data with information on cycling and helmet use for nearly 800,000 individuals from 1994 to 2014. We first confirm prior patterns from the United States that laws requiring youths to wear helmets significantly increased youth helmet use. We then provide the literature's first comprehensive evidence that “all‐age” bicycle helmet laws significantly increased both adult and youth helmet use by 50%–190% relative to pre‐reform levels, with larger effects for younger adults and less‐educated adults. All‐age helmet laws had modest effects at reducing cycling and increasing in‐home exercise during winter months among adults but did not meaningfully affect weight. Overall, our findings confirm that all‐age helmet laws can be effective at increasing population helmet use without significant unintended adverse health consequences. (JEL I18, I12, K32)