Decriminalization, Legalization, and Racial Gaps in Police Response to Youth Marijuana Offenses

We examine how Massachusetts’ decriminalization and legalization of marijuana affected police responses to youth under age 21, focusing on both how often incidents were formally handled and whether officers used summonses rather than on-view arrests. Using statewide data for 2007–2021 aggregated by race and quarter across the policy transitions, we implement an interrupted time-series design with seasonal controls and race – time interactions. Enforcement intensity declined sharply at each policy change for both White and Nonwhite youths and continued to fall thereafter. During legalization, the rate levels diverged where Nonwhite rates were higher at key policy milestones and declined more slowly. For enforcement modality, the odds of a summons rose over time overall, yet Nonwhite youths experienced a significant immediate drop at decriminalization and no clear increase after legalization, while White youths showed a sustained rise following legalization. Taken together, the policy shifts correspond with broad reductions in youth marijuana enforcement along with observed racial disparities in offense rates after legalization and in patterns in the use of summonses versus arrests.