Cannabis decriminalization in five states cut drug arrests by 75% without increasing youth use
A difference-in-difference analysis of five states found that cannabis decriminalization reduced youth drug-related arrests by 75% with similar effects for adults, while past-30-day cannabis use among youth showed no increase.
Quick Facts
What This Study Found
Researchers examined the effects of cannabis decriminalization in five states (Massachusetts 2008, Connecticut 2011, Rhode Island 2013, Vermont 2013, Maryland 2014) using federal crime statistics and Youth Risk Behavior Survey data.
Decriminalization was associated with a 75% reduction in drug-related arrests for youth (95% CI: 44-89%), with similar magnitude reductions for adult arrests.
Critically, decriminalization was not associated with any increase in past-30-day cannabis use prevalence among youth. The relative change was -0.2% (95% CI: -4.5% to 4.3%), effectively zero. This finding held both overall and in each individual decriminalization state.
The results suggest that decriminalization achieved its intended consequence (reducing arrest burden) without the commonly feared unintended consequence (increased youth use).
Key Numbers
75% reduction in youth drug arrests (95% CI: 44-89%). Past-30-day youth cannabis use change: -0.2% (95% CI: -4.5% to 4.3%). Five states analyzed: MA (2008), CT (2011), RI (2013), VT (2013), MD (2014). Study period: 2007-2015.
How They Did This
Difference-in-difference regression framework comparing trends in the five decriminalization states against states with no major cannabis policy changes during the observation period (2007-2015). Arrest data from federal crime statistics; youth use data from state Youth Risk Behavior Surveys.
Why This Research Matters
This study directly addresses the central concern about cannabis decriminalization: that reducing penalties will increase use, especially among young people. The finding that arrests dropped dramatically while youth use remained unchanged provides important evidence for policy debates.
The Bigger Picture
The arrest reduction has significant equity implications, as cannabis arrests disproportionately affect minority communities. The finding that these arrests can be reduced by 75% without increasing youth use challenges the deterrence argument that criminal penalties are necessary to prevent teen cannabis use.
What This Study Doesn't Tell Us
The observation period may be too short to capture longer-term changes in use patterns. Youth Risk Behavior Survey data is self-reported and school-based (misses dropouts). The five states may not represent all decriminalization contexts. The difference-in-difference approach assumes parallel trends would have continued without policy change.
Questions This Raises
- ?Do the effects persist beyond the initial observation period?
- ?Does decriminalization affect age of first use or frequency of use among those who do use?
- ?How do the arrest reductions distribute across racial and socioeconomic groups?
Trust & Context
- Key Stat:
- 75% reduction in youth drug arrests; zero change in youth cannabis use
- Evidence Grade:
- Well-designed difference-in-difference analysis across five states with multiple data sources provides strong quasi-experimental evidence on decriminalization effects.
- Study Age:
- Published in 2018 with data through 2015. Several of these states have since moved from decriminalization to full legalization.
- Original Title:
- Cannabis decriminalization: A study of recent policy change in five U.S. states.
- Published In:
- The International journal on drug policy, 59, 67-75 (2018)
- Authors:
- Grucza, Richard A(9), Vuolo, Mike(2), Krauss, Melissa J, Plunk, Andrew D, Agrawal, Arpana, Chaloupka, Frank J, Bierut, Laura J
- Database ID:
- RTHC-01668
Evidence Hierarchy
Follows a group of people over time to track how outcomes develop.
What do these levels mean? →Frequently Asked Questions
Did decriminalization lead to more teens using marijuana?
No. Past-30-day cannabis use among youth showed essentially zero change (-0.2%) after decriminalization in all five states studied. The feared increase in youth use did not materialize.
How much did arrests decrease?
Youth drug-related arrests dropped by 75% after decriminalization, with similar reductions for adults. This suggests the policy change achieved its primary intended goal of reducing the arrest burden.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-01668APA
Grucza, Richard A; Vuolo, Mike; Krauss, Melissa J; Plunk, Andrew D; Agrawal, Arpana; Chaloupka, Frank J; Bierut, Laura J. (2018). Cannabis decriminalization: A study of recent policy change in five U.S. states.. The International journal on drug policy, 59, 67-75. https://doi.org/10.1016/j.drugpo.2018.06.016
MLA
Grucza, Richard A, et al. "Cannabis decriminalization: A study of recent policy change in five U.S. states.." The International journal on drug policy, 2018. https://doi.org/10.1016/j.drugpo.2018.06.016
RethinkTHC
RethinkTHC Research Database. "Cannabis decriminalization: A study of recent policy change ..." RTHC-01668. Retrieved from https://rethinkthc.com/research/grucza-2018-cannabis-decriminalization-a-study
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.