Impact of BAC limit reduction on different population segments: a Poisson fixed effect analysis

Over the past few decades, several countries enacted the reduction of the legal blood alcohol concentration (BAC) limit, often alongside the administrative license revocation or suspension, to battle drinking-and-driving behavior. Several researchers investigated the effectiveness of these policies by applying different analysis procedures, while assuming population homogeneity in responding to these laws. The present analysis focuses on the evaluation of the impact of BAC limit reduction on different population segments. Poisson regression models, adapted to account for possible observation dependence over time and state specific effects, are estimated to measure the reduction of the number of alcohol-related accidents and fatalities for single-vehicle accidents in 22 U.S. jurisdictions over a period of 15 years starting in 1990. Model estimates demonstrate that, for alcohol-related single-vehicle crashes, (i) BAC laws are more effective in terms of reduction of number of casualties rather than number of accidents, (ii) women and elderly population exhibit higher law compliance with respect to men and to young adult and adult population, respectively, and (iii) the presence of passengers in the vehicle enhances the sense of responsibility of the driver.