In November 2012, Washington State voters passed
Initiative 502 to regulate and tax the use and sale of cannabis for persons twenty-one years of age and older. As part of I-502, WSIPP was directed to “conduct cost-benefit evaluations of the implementation” of the law. The evaluations must include measures of impacts on public health, public safety, cannabis use, the economy, the criminal justice system, and state and local costs and revenues.
Previous Work
A
preliminary report was released in September 2015. The second
required report was released in September 2017, and the third
required report was released in September 2023. The last mandated report is due in 2032.
Supplemental to the ongoing benefit-cost evaluation of cannabis legalization authorized by Initiative 502 in 2012, the 2018 Washington State Legislature directed WSIPP to conduct additional cannabis research. WSIPP was directed to update its
inventory of programs for the prevention and treatment of youth cannabis use; examine current data collection methods measuring the
use of cannabis by youth and potential ways to improve on these methods; and identify effective methods used to reduce or eliminate the
unlicensed cultivation or distribution of marijuana in jurisdictions with existing legal marijuana markets.
A
third required report covered the following topics:
reported substance use,
cannabis-related convictions,
traffic fatalities, and
substance use disorder diagnoses.
In 2023, we published an
interim report related to cannabis retail access and high school outcomes.
Recent Work
The Impact of Cannabis Retail Availability on Cannabis and Mental Health Outcomes Among Medicaid Recipients in Washington State published in September 2025, in this study, we explore the relationship between licensed cannabis retail availability in Washington State and healthcare outcomes related to cannabis use disorder (CUD) and mental health disorders, including depression, anxiety, bipolar, and psychotic disorders.
Current Work
Current ongoing work in service of our long-term benefit-cost evaluation of I-502 explores topics related to child welfare and workplace safety.