As part of the legalisation in Washington State that took effect in July 2014, the state legislature instructed the Washington State Institute of Public Policy (WSIPP) to publish periodic evaluations looking at factors in (at least) six named areas. These should inform a benefit-cost evaluation of the law.
On Friday 1 September, WSIPP published its report for 2017. The report lists preliminary findings for:
Data for other areas have yet to be obtained, or have been obtained but not yet fully analysed.
The analysis compares (a) the different counties within the State, noting per capita cannabis sales; and (b) Washington State with other similar states. Sales data do not represent all legal cannabis supply; home growing is allowed in Washington State for authorised medical (but not recreational) use. However, the medical and non-medical markets were integrated in July 2016, and now distinguishing the two is nearly impossible.
Drug use rates
In schools, use has been stable or fallen slightly, and cannabis is viewed as more difficult to access. There was no evidence that the amount of legal cannabis sales in a county affected cannabis use among school students, though 8th-graders in districts with more sales per capita were significantly less likely to report smoking cigarettes.
For adults, cannabis use has increased, whereas heavy alcohol use and cigarette use have remained stable or fallen. Those aged 21 and older living in counties with more sales per capita were significantly more likely to report current use (last 30 days) and heavy use (on 20 or more of the past 30 days). By contrast, those aged 18–20 living in counties with more sales were significantly less likely to report use of cannabis in the past 30 days, but the likelihood of heavy use was unaffected.
The number of state-funded admissions for cannabis use in Washington has been falling since 2008, and continues to do so. However, for those who were not referred by criminal justice, cannabis use admissions only started to decline in 2011. There is no evidence that the legalisation caused this change, or that the amount of sales in a county affected the number of cannabis abuse treatment admissions.
Convictions for cannabis possession
Cannabis possession remains illegal for those under 21. Nevertheless, misdemeanour cannabis possession convictions for this age group began to decline in 2012, reaching approximately half the level they had been over the previous 10 years. There was no evidence of effects of retail sales rates on convictions.
Report is available here: http://www.wsipp.wa.gov/ReportFile/1670/Wsipp_I-502-Evaluation-and-Benefit-Cost-Analysis-Second-Required-Report_Report.pdf
Technical appendix is available here: http://www.wsipp.wa.gov/ReportFile/1671/Wsipp_I-502-Evaluation-and-Benefit-Cost-Analysis-Second-Required-Report_Technical-Appendix.pdf