Variation in cannabis potency and prices in a newly legal market: evidence from 30 million cannabis sales in Washington state

Abstract

Aims To (1) assess trends and variation in the market share of product types and potency sold in a legal cannabis retail market, and (2) estimate how potency and purchase quantity influence price variation for cannabis flower. Design Secondary analysis of publicly available data from Washington State’s cannabis traceability system spanning July 7, 2014 to September 30, 2016. Descriptive statistics and linear regressions assessed variation and trends in cannabis product variety and potency. Hedonic regressions estimated how purchase quantity and potency influence cannabis flower price variation. Setting Washington State, USA. Participants (1) 44,482,176 million cannabis purchases, including (2) 31,052,123 cannabis flower purchases after trimming price and quantity outliers. Measurements Primary outcome measures were (1) monthly expenditures on cannabis, total delta-9-tetrahydrocannabinol (THC) concentration, and cannabidiol (CBD) concentration by product type; and (2) excise-tax-inclusive price per gram of cannabis flower. Key covariates for the hedonic price regressions included quantity purchased, THC, and CBD. Findings Traditional cannabis flowers still account for the majority of spending (66.6%), but the market share of extracts for inhalation increased by 145.8% between October 2014 and September 2016, now composing 21.2% of sales. The average THC-level for cannabis extracts is more than triple that for cannabis flowers (68.7% compared to 20.6%). For flower products, there is a statistically significant relationship between price per gram and both THC [coefficient = 0.012; 95% confidence interval (CI) = 0.011 to 0.013] and CBD [coefficient = 0.017; CI = 0.015 to 0.019]. The estimated discount elasticity is −0.06 [CI = −0.07 to −0.05]. Conclusions In the state of Washington, USA, the legal cannabis market is currently dominated by high-THC cannabis flower, and features growing expenditures on extracts. For cannabis flower, both THC and CBD are associated with higher per-gram prices, and there are small but significant quantity discounts.

Changes in cannabis potency and first-time admissions to drug treatment: a 16-year study in the Netherlands

“…These data were collected in a single geographical region, and improved global monitoring of cannabis potency and health-related outcomes may be necessary to investigate these associations elsewhere (Freeman & Swift, 2016). However, our findings highlight a cause for concern regarding the health impact of extremely potent cannabis concentrates (∼70% THC) which have very recently risen in popularity in some parts of the USA (Smart et al 2017). In a rapidly changing cannabis climate, it is essential that policy makers consider the effects of new legislation on cannabis potency and the incidence of cannabis-related harms.…”

The end of convergence in developmental patterns of frequent marijuana use from ages 18 to 30: An analysis of cohort change from 1976–2016

“…While CBD is believed to be neuroprotective, THC has been found to exacerbate alterations in brain regions such as the prefrontal cortex and hippocampus, and higher doses of marijuana use are particularly associated with such alterations (Lorenzetti et al, 2016). In states with legal marijuana markets (such as Washington), average THC levels for cannabis extracts have been found to be more than three times those for cannabis flowers (Smart et al, 2017). Frequent use of high-potency marijuana has been associated with dependence severity (Freeman and Winstock, 2015), and increases in potency have been linked with increases in first-time admissions to drug treatment for problems associated with cannabis (Freeman et al, 2018).…”

Cannabinoid Hyperemesis

“…A study from the Netherlands found that THC concentrations in cannabis products sold at retail outlets from 2000 to 2015 had roughly doubled from 2000 to 2015 [11]. New products on the market are even higher in THC: cannabis extracts (used for “dabbing”) have more than triple the THC content of the buds or other plant parts commonly used for smoking (68.7 vs. 20.6%) [12]. However, it is hard to discuss cannabinoids as if they were one single substance; even among botanical marijuana offerings, there are numerous varieties and diverse methods of consumption (smoking, “vaping,” edibles).…”