Other covariates were selected based on factors known to be associated with risk of substance use disorders, and possibly correlated with the state decisions to change their MLDA laws in specific years. All analyses controlled for gender, survey, self-identified non-Hispanic Black or Hispanic race or ethnicity, indicators for five roughly equal-population quintiles of age at assessment (20–29, 30–34, 35–39, 40–44, and 45–54 years of age), and unordered indicators for single year of birth and either state of residence or state of birth. Some analyses also controlled for a binary indicator of (subject-reported) maternal or paternal alcohol problems, and inflation-adjusted state beer taxes in effect when the subject was 18 years old (Beer Institute 2008). Other analyses investigated the role of demographic factors in later adulthood that might lie in the causal pathway between MLDA exposure and drug or alcohol use; these factors included age of onset of drinking (both as a linear mesure, and using unordered indicators for the following categories: under 14, 14–15, 16–17, 18, 19, 20, 21, > 21, and lifetime abstention), educational attainment, whether currently employed or
