Assessing the Impact of Twenty Underage Drinking Laws.

Objective: Over the last two decades, many states have adopted several of the 20 laws that aim to control youth access to and possession of alcohol and prevent underage drinking in the United States. However, many of these laws have not been evaluated since their adoption. The objective of this study was to determine which minimum legal drinking age 21 (MLDA-21) laws currently have an effect on underage drinking-and-driving fatal crashes.

Method: We updated the effective dates of the 20 MLDA-21 laws examined in this study and used scores of each law's strengths and weaknesses. Our structural equation model included the 20 MLDA-21 laws, impaired driving laws, seat belt safety laws, economic strength, driving exposure, beer consumption, and fatal crash ratios of drinking-to-nondrinking drivers under age 21.

Results: Nine MLDA-21 laws were associated with significant decreases in fatal crash ratios of underage drinking drivers: possession of alcohol (-7.7%), purchase of alcohol (-4.2%), use alcohol and lose your license (-7.9%), zero tolerance .02 blood alcohol concentration limit for underage drivers (-2.9%), age of bartender ≥21 (-4.1%), state responsible beverage service program (-3.8%), fake identification support provisions for retailers (-11.9%), dram shop liability (-2.5%), and social host civil liability (-1.7%). Two laws were associated with significant increases in the fatal crash ratios of underage drinking drivers: prohibition of furnishing alcohol to minors (+7.2%) and registration of beer kegs (+9.6%).

Conclusions: The nine effective MLDA-21 laws are estimated to be currently saving approximately 1,135 lives annually, yet only five states have enacted all nine laws. If all states adopted these nine effective MLDA-21 laws, it is estimated that an additional 210 lives could be saved every year.