The purpose of this study is to take advantage of the “natural experiments” afforded by changes in MLDA to assess long-term effects of state MLDA policies in effect during adolescence/early adulthood on later suicide and homicide rates. The quasi-experimental approach allows for inferences about the role of the policy environment, independent of genetic and other individual-level characteristics, providing that MLDA law can be considered to be randomly assigned at the individual level. Our focus is on the 1990–2004 period. During this time, MLDA changes had been completed, and any effect of having been legally permitted to drink prior to age 21 can only be attributed to earlier exposure to these policies.
