The relationship of underage drinking laws to reductions in drinking drivers in fatal crashes in the United States

This study reports on an effort to evaluate and interrelate the existence and strength of two core laws and 14 expanded laws designed to (a) control the sales of alcohol, (b) prevent possession and consumption of alcohol, and (c) prevent alcohol impaired driving by youth aged 20 and younger. Our first analysis determined if the enactment of the possession and purchase laws (the two core minimum legal drinking age laws) was associated with a reduction in the ratio of drinking to nondrinking drivers aged 20 and younger who were involved in fatal crashes controlling for as many variables as possible. The ANOVA results suggest that in the presence of numerous covariates, the possession and purchase laws account for an 11.2% (p = 0.041) reduction in the ratio measure. Our second analysis determined whether the existence and strength of any of the 16 underage drinking laws was associated with a reduction in the percentage of drivers aged 20 and younger involved in fatal crashes who were drinking. In the regression analyses, making it illegal to use a false identification to purchase alcohol was significant. From state to state, a unit difference (increase) in the strength of the False ID Use law was associated with a 7.3% smaller outcome measure (p = 0.034).