The Legacy of Minimum Legal Drinking Age Law Changes: Long‐Term Effects on Suicide and Homicide Deaths Among Women

Abstract

Background Prior to the establishment of the uniform drinking age of 21 in the United States, many states permitted legal purchase of alcohol at younger ages. Lower drinking ages were associated with several adverse outcomes, including elevated rates of suicide and homicide among youth. The objective of this study is to examine whether individuals who were legally permitted to drink prior to age 21 remained at elevated risk in adulthood. Methods Analysis of data from the U.S. Multiple Cause of Death files, 1990–2004, combined with data on the living population from the U.S. Census and American Community Survey. The assembled data contained records on over 200,000 suicides and 130,000 homicides for individuals born between 1949 and 1972, the years during which the drinking age was in flux. Logistic regression models were used to evaluate whether adults who were legally permitted to drink prior to age 21 were at elevated risk for death by these causes. A quasi-experimental analytical approach was employed which incorporated state and birth year fixed effects to account for unobserved covariates associated with policy exposure. Results In the population as a whole, we found no association between minimum drinking age and homicide or suicide. However, significant policy-by-sex interactions were observed for both outcomes, such that women exposed to permissive drinking age laws were at higher risk for both suicide (OR=1.12; 95% CI 1.05, 1.18, p=0.0003) and homicide (OR=1.15; 95% CI 1.04, 1.25; p=0.0028). Effect sizes were stronger for the portion of the cohort born after 1960, whereas no significant effects were observed for women born prior to 1960. Conclusions Lower drinking ages may result in persistent elevated risk for suicide and homicide among women born after 1960. The national drinking age of 21 may be preventing about 600 suicides and 600 homicides annually.

Did the 18 Drinking Age Promote High School Dropout? Implications for Current Policy

“…If cross-state migration is uncorrelated with MLDA and high school dropout, as we assumed, our estimates likely underestimate the true relationship between permissive MLDA and high school dropout. We have established that this is a reasonable assumption in previous work (Grucza et al, 2012;Norberg et al, 2009).…”

“…Further, our earlier work suggested that migration would bias our results toward a false-positive result only under very high selective migration: more than 25% (Grucza et al, 2012). Because there was no evidence that any selective migration based on MLDA exposure occurred, it was unlikely that estimating MLDA exposure was a source of confounding for our analyses.…”

“…MLDA exposure was determined as described elsewhere (Grucza et al, 2012;Norberg et al, 2009;Plunk et al, 2013), using a variety of sources, including peer-reviewed research (Du Mouchel et al, 1987;O'Malley & Wagenaar, 1991;Wagenaar, 1982), the Statewide Availability Data System (Ponicki, 2004), and news sources (Associated Press, 1996). We assessed three different thresholds of MLDA exposure in our analyses: (a) any permissive MLDA, to include the legal drinking age of 18, 19, or 20; (b) a threshold including the drinking ages of 18 and 19; and (c) a threshold that only considered the impact of the MLDA of 18.…”

Long-Term Impact on Alcohol-Involved Crashes of Lowering the Minimum Purchase Age in New Zealand

“…To the best of our knowledge, no previous study has analyzed the long-term effects of a lowered purchase age (aside from cohort studies with a different focus). 11,12 Lowering the purchase age had no impact on fatal alcohol-involved crashes among drivers aged 18 to 19 years compared with drivers aged 20 to 24 years. Numbers of alcohol-involved fatal crashes were smaller, which may have reduced statistical power.…”

“…5--- 10 We could not find any published study reporting the long-term relationships between lowering the legal age limit and harms in which the postlaw change period comprised 10 or more years of data (aside from studies finding cohort effects as affected age groups grew older). 11,12 The minimum legal purchase age for alcohol in New Zealand was lowered from 20 to 18 years 13 on December 1, 1999, providing a context in which to study the longer term effects of such a law change.…”