Working Paper: NBER ID: w24644
Authors: Christopher S. Carpenter; Casey Warman
Abstract: 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 1994-2014. We first confirm prior patterns from the US 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 to 190 percent 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. Finally, we find larger effects of helmet laws at increasing helmet use for adults with children in the household, consistent with role-modeling behavior. Overall our findings confirm that all-age helmet laws can be effective at increasing population helmet use without significant unintended adverse health consequences.
Keywords: bicycle helmet laws; public health; Canada; helmet use; cycling behavior
JEL Codes: I18; Z18; Z2
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| all-age helmet laws (R48) | helmet use (R48) |
| all-age helmet laws (R48) | cycling participation (R48) |
| all-age helmet laws (R48) | in-home exercise during winter months (I19) |
| all-age helmet laws (R48) | weight (I14) |
| all-age helmet laws (R48) | helmet use among adults with children (R48) |