to see how lessons from tobacco control can be applied to
Declaration of interests
Keywords Canada, cannabis, commercialization,
tobacco, United States, Uruguay.
School of Public Policy, University of Maryland,
College Park, MD, USA
Submitted 29 May 2017; ﬁnal version accepted 15 June 2017
1. Hall W., Kozlowski L. T. The diverging trajectories of cannabis
and tobacco policies in the United States: reasons and possible
implications. Addiction 2018; 113:595–601.
2. Caulkins J., Kilmer B., Kleiman M., MacCoun R., Midgette G.,
Oglesby P. et al. Considering marijuana legalization [internet].
RAND Corporation, 2015. Available at: http://www.rand.
org/pubs/research_reports/RR864.html (accessed 24 April
3. Ramsey G. Getting Regulation Right: Assessing Uruguay’s
Historic Cannabis Initiative. Washington, DC: Washington
Ofﬁce on Latin America; 2016.
4. Pardo B. Cannabis policy reforms in the Americas: a compar-
ative analysis of Colorado, Washington, and Uruguay. Int J
Drug Policy 2014; 25:727–35.
5. Decorte T. Cannabis social clubs in Belgium: organizational
strengths and weaknesses, and threats to the model. Int J Drug
Policy 2015; 26:122–30.
6. Decorte T., Pardal M., Queirolo R., Boidi M. F., Avilés C. S.,
Franquero Ò. P. Regulating cannabis social clubs: a compara-
tive analysis of legal and self-regulatory practices in Spain,
Belgium and Uruguay. Int J Drug Policy 2017; 43:44–56.
7. Congreso de la Republica Oriental del Uruguay. Control del
Tabaquismo [Tobacco Control Laws]. 10 March 2008.
Montevideo, Uruguay: Congreso de la Republica Oriental del
8. Castaldi M., Esposito A. Phillip Morris loses tough-on-to-
bacco lawsuit in Uruguay. Reuters [internet]. Available
suit-idUSKCN0ZO2LZ (accessed 9 July 2016).
9. Government of Canada Health Canada and the Public Health
Agency of Canada. A framework for the legalization and
regulation of cannabis in Canada [internet]. 2016. Available
groupe-etude/framework-cadre/index-eng.php (accessed 14
10. Benzie R., MacCharles T., Campion-Smith B., Ferguson R.
Cannabis day is coming soon. What’s next for pot plans in
Ontario? Toronto Star. thestar.com [internet]. 2017 Mar 27.
Available at: https://www.thestar.com/news/queenspark/
29 May 2017).
11. Aliferis L. California raises age of tobacco purchase to 21
and tightens vaping rules. NPR [internet]. 2016 May 5.
Available at: http://www.npr.org/sections/health-shots/
purchase-to-21-and-tightens-vaping-rules (accessed 20
12. Chaloupka F. J., Pacula R. L., Farrelly M. C., Johnston L. D.,
O’Malley P. M. Do higher cigarette prices encourage youth
to use marijuana? [internet]. National Bureau of Economic
Research; 1999 Feb. Report no.: 6939. Available at: http://
www.nber.org/papers/w6939 (accessed 30 May 2017).
13. Cameron L., Williams J. Cannabis, alcohol and cigarettes: sub-
stitutes or complements? Econ Rec 2001; 77:19–34.
14. Patton G. C., Coffey C., Carlin J. B., Sawyer S. M., Lynskey M.
Reverse gateways? Frequent cannabis use as a predictor of to-
bacco initiation and nicotine dependence. Addiction 2005;
15. Bélanger R. E., Akre C., Kuntsche E., Gmel G., Suris J.-C.
Adding tobacco to cannabis—its frequency and likely implica-
tions. Nicotine Tob Res 2011; 13:746–
16. Barry R. A., Glantz S. A public health framework for legalized
retail marijuana based on the US experience: avoiding a new
tobacco industry. PLOS Med 2016; 13: e1002131.
17. Subritzky T., Pettigrew S., Lenton S. Issues in the implementa-
tion and evolution of the commercial recreational cannabis
market in Colorado. Int J Drug Policy 2016; 27:1–12.
THE TRAJECTORIES OF CANNABIS AND
TOBACCO POLICIES IN THE UNITED STATES,
URUGUAY, CANADA AND PORTUGAL:
IS MORE CROSS-SUBSTANCE LEARNING
POSSIBLE OUTSIDE THE UNITED STATES?
The diverging trajectories of cannabis and tobacco regulation
in the United States today do not appear to reﬂect a global
trend. Uruguay, Canada and Portugal all show more cross-
substance learning and more aligned policy trajectories.
Hall & Kozlowski  outline diverging trajectories of
cannabis and tobacco regulation in the United States
towards legalized commercial cannabis markets and
prohibitionist tobacco policies, respectively. They also
raise legitimate concerns about the lack of cross-sub-
stance learning regarding, for example, the public
health risks of for-proﬁt models. This commentary con-
siders the international implications of Hall &
Kozlowski’s  analysis. Speciﬁcally, it asks: are the di-
verging trajectories and barriers to cross-substance
learning in the United States reﬂective of a global
trend in cannabis and tobacco regulation?
International generalizability is important, as policy
processes do not occur in a vacuum, with policy trajecto-
ries shaped by national factors such as legal and constitu-
tional arrangements . Both appear critical for
understanding the trajectories of cannabis legalization in
the United States today [3,4]. For example, as outlined by
© 2017 Society for the Study of Addiction Addiction, 113,602–609