We previously reported that the 2018 Canadian Cannabis Act, allowing youth to possess up to 5 g dried cannabis or equivalent for personal use/sharing, was associated with short-term (76 days) post-legalization reduction in police-reported cannabis-related crimes among youth. To establish whether the change might be sustained, we now estimate this association during a much longer time period by including an additional three years of post-legalization data.
Using national daily police-reported criminal incident data from January 1, 2015–December 31, 2021 from the Canadian Uniform Crime Reporting Survey (UCR-2), the study employed Seasonal Autoregressive Integrated Moving Average (SARIMA) time series models to assess the associations between legalization and youth (12–17 years) cannabis-related offenses (male, n = 34,508; female, n = 9529).
Legalization was associated with significant reductions in both male and female police-reported cannabis-related offenses: females, 4.04 daily incidents [95% confidence interval (CI), 3.08; 5.01], a 62.1% decrease [standard error (se), 34.3%]; males, 12.42 daily offenses (95% CI, 8.99; 15.86), a reduction of 53.0% (se, 22.7%). There was no evidence of associations between cannabis legalization and patterns of property or violent crimes.
Results suggest that the impact of the Cannabis Act on reducing cannabis-related youth crimes is sustained, supporting the Act’s objectives to reduce cannabis-related criminalization among youth and associated effects on the Canadian criminal justice system.
Canada’s Government implemented aspects of cannabis legalization with the Cannabis Act on October 17, 2018 (Parliament of Canada, 2018). Youth were a key focus of the Act [(Health Canada, 2016) (p. 13); see (Callaghan et al., 2021)], which aimed in part to reduce the harm of criminalization of young people who use cannabis. In this regard, the Cannabis Act permits youth (aged 12–17 years) to possess up to 5 g of dried cannabis or equivalent for personal use or sharing.
Using 2015–2018 criminal-incident data from the Canadian Centre for Justice and Community Safety Statistics (CCJCSS) Uniform Crime Reporting Survey (UCR-2) – the national database for police-reported criminal incidents in Canada, our preliminary work found that the implementation of the Cannabis Act was associated with immediate decreases of 55%–65% in police-reported cannabis-related crimes among male and female youth (aged 12–17 years) (Callaghan et al., 2021). These findings provided early evidence supporting the Act’s objectives to reduce cannabis-related criminalization among young people and the concomitant impacts on the Canadian criminal justice system. Nonetheless, a key limitation of this prior work was the inclusion of only a very short post-legalization period of 76 days – a time span obviating the estimation of longer-term effects of legalization on cannabis-related criminal incidents. The current project aims to extend our original study by providing an estimation over a much longer time period with the inclusion of an additional three years of post-legalization data (2015–2021).
Overview of method and analytic strategy
The UCR-2 survey data used in the study are anonymized, publicly available, and the confidentiality and privacy of personal information are protected by the Canadian Statistics Act. As a result, the current study is exempt from the Centre for Addiction and Mental Health (CAMH) Research Ethics Board review.
The current study uses a similar method and analytic strategy as described in detail in our prior publication (Callaghan et al., 2021), but with a much longer post-legalization follow-up of
The analytical results and figures in the current paper include preliminary criminal incident data (limited to January 1, 2015-December 31, 2018) previously published in our prior work on the same topic (Callaghan et al., 2021) that are extended in the current study.
Table 1 shows the number of criminal incidents across pre- and post-legalization periods. Legalization was associated with a significant decrease of 12.42 (95% CI, 8.99; 15.86, p < 0.001) male cannabis-related criminal incidents per
Previously we showed, in a study using 76 days of post-legalization data, that implementation of the Cannabis Act was associated with a short-term 55–65% reduction in police-reported cannabis-related criminal incidents among youth (Callaghan et al., 2021). In the current study, we found that the drop in cannabis offenses associated with legalization is similar to that of our prior work, both in absolute and relative terms – but, most importantly, that this initial legalization effect endured
This research was supported in part by a Canadian Institutes of Health Research (CIHR) Project Grant (PJT 180292) awarded to the first author (RCC).
CRediT authorship contribution statement
RCC conceived of the study design, acquired study data, and oversaw all aspects of the study, including the data analysis, preparation and submission of the final manuscript. MS completed the data analysis and made substantial contributions to the initial and final versions of the manuscript, especially in the interpretation of the statistical results. AH made substantial contributions to the preparation of the final version of the manuscript, especially in the interpretation of the study
Declaration of Competing Interest
This research was supported in part by a Canadian Institutes of Health Research (CIHR) Project Grant (PJT 180292) awarded to the first author (RCC). In relation to the manuscript, the authors have no competing interests to declare.
The study team would like to thank Kathy AuCoin and Philip Walsh at the Statistics Canada Canadian Centre for Justice and Community Safety Statistics for their support of the project.