For this study, researchers utilized data from 2000-2013 on 12th grade students drawn from the larger Monitoring the Future (MTF) study, an ongoing, annual national survey (since 1975) that studies the substance use behaviors of adolescents. The researchers also gathered data on GDL laws obtained via the Insurance Institute for Highway Safety. They then conducted a series of logistic regression models that included fixed effects for year and state, and adjusted for demographic characteristics, school characteristics, and other state alcohol policies.
Nearly 12 percent of respondents reported driving in the previous two weeks after drinking alcohol, 17 percent reported riding with a driver who drank alcohol, and seven percent reported driving after binge drinking. More than half of the students lived in a state with a “good” GDL law. Modeling suggests that the effects of GDLs extend beyond driving-related risks to include other drinking-related behaviors that pose immediate or delayed health risks for young people. The authors speculate that GDLs may dictate social norms and expectations for youth risk behaviors, and suggest that they should be maximized throughout the U.S.