Adam Darnell - May 2019

The 2018 Washington State Legislature directed WSIPP to conduct additional cannabis research, supplemental to the ongoing benefit-cost evaluation of cannabis legalization authorized by Initiative 502 in 2012. As part of this supplemental work, WSIPP was directed to examine current data collection methods measuring the use of marijuana by youth and potential ways to improve on these methods. In this report, we focused on the Washington Healthy Youth Survey, the primary source of data on cannabis use among Washington youth. We reviewed the evidence for harmful consequences of cannabis use focusing on how cannabis use was measured, and we examined recently developed surveys that reflect the state-of-the-art in survey measurement of marijuana use. With this information, we identified a set of potential improvements to the HYS while considering the practical limitations of revisions to an existing survey.

Adam Darnell, Michael Hirsch, Paige Wanner - August 2019

The 2018 Washington State Legislature directed WSIPP to conduct additional cannabis research, supplemental to the ongoing benefit-cost evaluation of cannabis legalization authorized by Initiative 502 in 2012. As part of the new assignments, WSIPP was directed to examine effective methods for suppressing unlicensed cultivation and distribution of marijuana in jurisdictions with legal markets. We found very little evidence on that topic. Instead, we identified numerous factors that could contribute to the survival of the illicit marijuana market in the context of legalization, such as continuing prohibitions in other states and regulations that reduce the competitive advantage of the legal market. We examined key regulatory features in the nine states with licensed non-medical cannabis supply systems and found that states varied widely in the level of restriction imposed on legal supply systems. We conclude by outlining a practical strategy for monitoring illicit market reductions as the state’s approach to legalization develops.

Bailey Ingraham, Amani Rashid - June 2023

In November 2012, Washington State voters passed Initiative 502 (I-502), which legalized limited possession, private use, and commercial sales of cannabis for adults. In this report, we describe the evolution of cannabis-related policy, revenues, and expenditures over the past decade.

We first describe the implementation of I-502 and summarize major cannabis-related policy milestones through the fiscal year 2022. In addition, we detail aspects of the Washington cannabis market structure and regulatory rules and compare components of non-medical cannabis (NMC) legalization nationwide. Second, we describe cannabis-related sales, excise tax revenues, and spending of those revenues over the last decade. In fiscal year 2022, cannabis retailers sold nearly $1.4 billion in cannabis products, and just over half a billion dollars were generated in excise tax revenues. Most of these revenues are transferred to the general fund and state basic health plan trust, and less than 20% goes to state agencies for prevention, healthcare, research, and cannabis industry oversight. Since fiscal year 2016, this distribution of expenditures has not significantly changed, although the total dollar amount of cannabis-related revenue and expenditure has nearly tripled.

Adam Darnell, Rebecca Goodvin, Matt Lemon, Marna Miller - December 2016

Initiative 502 (I-502) legalized recreational cannabis for adults in Washington State. The law directs the Washington State Institute for Public Policy (WSIPP) to conduct a benefit-cost evaluation of the implementation of I-502.

In this report we summarize the research evidence for 51 programs for the prevention or treatment of youth cannabis use. The programs reviewed include those nominated by DBHR as well as programs from WSIPP’s current set of inventories that have evidence for cannabis outcomes.

Adam Darnell, Rebecca Goodvin, Sara del Moral, Casey Hicks, Paige Wanner, Eva Westley - December 2018

Initiative 502 (I-502) legalized recreational cannabis for adults in Washington State. The law directs a portion of cannabis revenues to be spent on substance abuse prevention and treatment services that have been demonstrated to be effective. Specifically, state law requires at least 85% of programs funded by cannabis revenues to be evidence-based or research-based and up to 15% to be promising practices. In this inventory, we rate the research evidence for programs intended for the prevention or treatment of youth substance use, and we identify those specifically effective for marijuana. The 2018 Washington State Legislature directed WSIPP to update this inventory. This is the third update in the series.

Eva Westley, Marna Miller, Rebecca Goodvin, Casey Hicks - December 2019

Initiative 502 (I-502) legalized recreational cannabis for adults in Washington State. The law directs a portion of cannabis revenues to be spent on substance abuse prevention and treatment services that have been demonstrated to be effective. Specifically, state law requires at least 85% of programs funded by cannabis revenues to be evidence-based or research-based, and up to 15% to be promising practices.

In this inventory, we rate the research evidence for programs intended for the prevention or treatment of youth substance use, and we identify those specifically effective for reducing marijuana use. The 2018 Washington State Legislature directed WSIPP to update this inventory. This is the fourth update in the series.

Adam Darnell, Kristofer Bitney - September 2017

Initiative 502, passed by Washington voters in November 2012, legalized the limited adult possession and private consumption of cannabis, as well as its licensed production and sale. The initiative directs WSIPP to evaluate the impact of the law in a series of reports between 2015 and 2032.

In this second required report we address preliminary findings from analyses of effects of I-502 on non-monetary outcomes. We used two main analysis strategies. We examined the effect of I-502 enactment on cannabis abuse treatment admissions, comparing Washington to similar non-legalizing states before and after I-502 enactment. We also examined how local differences in the amount of legal cannabis sales affected cannabis abuse treatment admissions, youth and adult substance use, and drug-related criminal convictions.

These analyses represent an intermediate step towards the ultimate benefit-cost evaluation of I-502 that is required by the law.

Sean Hanley - November 2013

The Washington State Institute for Public Policy is directed to conduct a benefit-cost analysis of the implementation of I-502, which legalizes recreational cannabis use for adults within the state. As a preliminary step, we analyzed population-level data to begin monitoring four key indicators of cannabis use prior to implementation.

We used data from the 2002 to 2011 administrations of the National Survey on Drug Use and Health to examine trends in the prevalence of current cannabis use, lifetime cannabis use, age of initiation, and cannabis abuse or dependency. We examined these trends separately for youth and adults in Washington, and also provide estimates for Colorado (the other state that has legalized recreational cannabis use) and the rest of the United States (US).

Examining trends in this manner will allow us to monitor whether the implementation of I-502 appears to affect these key indicators of marijuana use over time. Although more sophisticated analyses will be required for us to evaluate the policy, these initial trends provide a baseline to compare future data against. The prevalence of cannabis use in the past 30 days—a key indicator of the proportion of people who are current cannabis users—appears to be on the rise in recent years among both youth and adults in Washington, Colorado, and the US. The other indicators of use appear to be relatively stable or increasing slightly over time. In general, the estimates from Washington are slightly higher than the US and slightly lower than Colorado.

We will continue to monitor these trends over time within the context of our larger benefit-cost analysis to examine whether the new policy appears to affect marijuana use rates within the state.

Adam Darnell - September 2015

Initiative 502, passed by Washington voters in November 2012, legalized the limited adult possession and private consumption of cannabis, as well as its licensed production and sale. The initiative directs WSIPP to evaluate the impact of the law in a series of reports between 2015 and 2032.

It is too early in the history of I-502 to evaluate outcomes. This first required report describes the research plan for the overall study and presents preliminary data on the status of implementation of the law as of June 30, 2015. Ultimately, WSIPP’s evaluation will include a full descriptive study of implementation; an outcome study to identify causal effects of the law on a range of outcomes (e.g., substance use and abuse, health, criminal justice, traffic safety); and a benefit-cost analysis of the net economic impact of the law.