Alcohol purchase age and road safety

Eric Crampton blogs on a recent working paper by Stefan Boes and Steve Stillman:

Overall, we find no evidence that changing the drinking age from 20 to 18 led to more vehicular accidents or alcohol-related accidents among teens. This is true both in the short-run following the law change and when examining cumulative accidents for the affected cohorts. We find that accidents do increase after one’s 18th birthday, but this appears to be a short-run phenomenon. Finally, our parametric regression models suggest that reducing the drinking age led to a decline in risky driving by youth who were already 15 at the time of the law change but had no longer-run impacts on youth risky driving among younger cohorts. We speculate that this occurred because of the extensive public discussion about the drinking age change that took place and because teens are likely to be particularly focused on the near future. We also present supportive evidence from infrequent health surveys showing a similar pattern for alcohol consumption among different youth cohorts. Our results support the argument that the legal drinking age can be lowered without leading to increases in detrimental outcomes for youth and call into question previous studies that have made policy recommendations by extrapolating from results identified using age-based RDDs.

Of interest is that youth drink driving rates continue to drop. A 2012 Stuff article shows a drop from 6,414 offences to 3,091.