Why Changes in Price Matter When Thinking About Marijuana Policy: A Review of the Literature on the Elasticity of Demand

Where Do Adults in the United States Obtain Cannabis? A Nationally Representative Study Examining the Relationships Between Sociodemographic Factors, Cannabis Use Characteristics and Sources of Cannabis

OBJECTIVE

Characterization of population subgroups based on where they acquire cannabis is unexplored. We examine relationships between sociodemographic characteristics, cannabis use modality, risky cannabis use, and source of cannabis.

METHOD

Analyzing a representative sample (unweighted n = 8,089) of U.S. adults living in medical cannabis-permitting states with past-year cannabis use from the 2021 National Survey on Drug Use and Health, we determined source of last cannabis used. Outcome groups were purchased from a dispensary, purchased from another source, or nonpurchased source. Incorporating the complex survey design, descriptive statistics and adjusted multinomial logistic regressions evaluated associations between sociodemographic, individual cannabis use characteristics, and source of cannabis. Secondary analyses described cannabis purchasing characteristics among the subsample who last purchased cannabis.

RESULTS

Purchasing from a dispensary was the most common source of cannabis (42.5%). Significant relationships between sociodemographic characteristics, cannabis use modality, risky cannabis use, and source of cannabis were found. Recent cannabis initiates and those with cannabis vaporizer use had an increased likelihood of purchasing cannabis from a dispensary. Purchasing from a nondispensary source was most likely among those with daily cannabis use, past-month blunt use, past-year driving under the influence, cannabis use disorder, and cannabis and alcohol co-use. Among those purchasing cannabis, joints and other forms of cannabis were more likely to be purchased from a dispensary than purchased from other sources.

CONCLUSIONS

We identified key sociodemographic and cannabis use characteristics that may influence where individuals obtain cannabis, which are important for cannabis behavior surveillance and cannabis use prevention and intervention strategies to consider.

Adolescent Advertising Exposure to Cannabis Products in Rural Oklahoma via Medical Dispensaries

OBJECTIVE

We assess cannabis advertising exposure among adolescents in rural Oklahoma from medical dispensaries.

METHOD

Our mixed-methods study identified medical dispensaries within a 15-minute drive time of rural Oklahoma high schools. Study staff completed observational data collection forms and took photographs of each dispensary. Quantitative data from the forms and qualitative coding of photographs were used to describe dispensary characteristics and likely advertising exposure for adolescents.

RESULTS

Ninety-two dispensaries were identified across 20 rural communities. The majority presented as retail spaces (n = 71). Product (n = 22) and price promotions (n = 27) were common. Coding of dispensary photographs found that product promotions advertised cannabis use modalities, with cannabis flower being the most common (n = 15), followed by edibles (n = 9) and concentrates (n = 9). Among dispensaries with price promotions, discounts (n = 19) and prices under $10 (n = 14) were common.

CONCLUSIONS

Sampled rural medical dispensaries present as retail spaces and are a likely source of adolescent cannabis advertising exposure.

Concurrent validity of the marijuana purchase task: a meta-analysis of trait-level cannabis demand and cannabis involvement

BACKGROUND AND AIMS

The Marijuana Purchase Task (MPT) is increasingly used to measure cannabis reinforcing value and has potential use for cannabis etiological and regulatory research. This meta-analysis sought to evaluate for the first time the MPT's concurrent validity in relation to cannabis involvement.

METHODS

Electronic databases and pre-print repositories were searched for MPT studies that examined the cross-sectional relationship between frequency and quantity of cannabis use, problems, dependence, and five MPT indicators: intensity (i.e. unrestricted consumption), Omax (i.e. maximum consumption), Pmax (i.e. price at which demand becomes elastic), breakpoint (i.e. first price at which consumption ceases), and elasticity (i.e. sensitivity to rising costs). Random effects meta-analyses of cross-sectional effect sizes were conducted, with Q tests for examining differences by cannabis variables, meta-regression to test quantitative moderators, and publication bias assessment. Moderators included sex, number of MPT prices, variable transformations, and year of publication. Populations included community and clinical samples.

RESULTS

The searches yielded 14 studies (n = 4077, median % females: 44.8%: weighted average age = 29.08 [SD = 6.82]), published between 2015 and 2022. Intensity, Omax , and elasticity showed the most robust concurrent validity (|r's| = 0.147-325, ps < 0.014) with the largest significant effect sizes for quantity (|r| intensity = 0.325) and cannabis dependence (|r| Omax  = 0.320, |r| intensity = 0.305, |r| elasticity = 0.303). Higher proportion of males was associated with increased estimates for elasticity-quantity and Pmax -problems. Higher number of MPT prices significantly altered magnitude of effects sizes for Pmax and problems, suggesting biased estimations if excessively low prices are considered. Methodological quality was generally good, and minimal evidence of publication bias was observed.

CONCLUSIONS

The marijuana purchase task presents adequate concurrent validity to measure cannabis demand, most robustly for intensity, Omax , and elasticity. Moderating effects by sex suggest potentially meaningful sex differences in the reinforcing value of cannabis.

Delta-8 tetrahydrocannabinol: a scoping review and commentary

BACKGROUND AND AIMS

Delta-8 tetrahydrocannabinol (THC) is a psychoactive substance from the Cannabis plant that has been rising in popularity in the United States since the 2018 US Farm Bill implicitly legalized it. This study reviewed research from peer-reviewed and non-peer-reviewed (e.g. anecdotal and news) reports related to delta-8 THC to summarize current knowledge and implications for public health and safety.

METHODS

A scoping review was conducted using PubMed, Scopus, Google Scholar and Google as search engines, leading to the identification of 103 documents that were summarized. The themes that emerged were (1) legality, (2) use (popularity, motives, psychoactivity/potency, benefits/consequences), (3) synthesis (byproducts, laboratory testing) and (4) retail (availability, price, packaging, youth-oriented marketing). A second author independently coded 20% of the documents, which verified the categorization of articles by these emergent themes.

RESULTS

Most research used animal/cell models or focused upon ways to identify the chemical structure of delta-8 THC in various products. Findings suggest that people often use delta-8 THC as a substitute for other substances. Anecdotally, delta-8 THC is a less potent psychoactive than delta-9 THC; however, several negative consequences have been reported. There is no federal age restriction for purchase/possession of delta-8 THC products. Delta-8 THC is readily accessible on-line, is typically less expensive than delta-9 THC and is often marketed in ways that would seemingly appeal to children. There are no regulations on synthesis, resulting in products being contaminated and/or yielding inconsistent effects. There have been thousands of calls to US poison control centers due to accidental delta-8 THC exposure among minors.

CONCLUSIONS

Most research on delta-8 THC is largely anecdotal, not peer-reviewed and does not involve human subjects. Future research should examine delta-8 THC use using nationally representative samples to more clearly understand the prevalence and consequences of use. Laws are needed to mitigate the risks of using delta-8 THC, particularly quality control of synthesis and minimum purchase age.

Risky cannabis use is associated with varying modes of cannabis consumption: Gender differences among Canadian high school students

BACKGROUND

Our objective was to explore associations between indicators of more risky cannabis use (i.e., solitary use, frequent use, and younger age of initiation) and different modes of cannabis use (i.e., smoking, vaping and/or edibles).

METHODS

Data were gathered from a large sample of Canadian youth in Alberta, British Columbia, Ontario, and Quebec who participated in Year 8 (2019-20) of the COMPASS study, and who reported using cannabis in the past year (n = 4,763). Generalized estimating equations were used to examine associations between risky cannabis use and modes of cannabis use, stratified by gender.

RESULTS

Overall, 38% of students reported using multiple modes of cannabis use. Consistent among both males and females, students who used cannabis alone (35%) and at a higher frequency (55%) were more likely to use multiple modes than smoking only. Among females, those who used cannabis alone were more likely to report using edibles only compared to smoking only (aOR=2.27, 95%CI=1.29-3.98). Earlier cannabis use initiation was associated with lower likelihood of vaping cannabis only among males (aOR=0.25; 95%CI = 0.12-0.51), and lower likelihood of using edibles only among females (aOR=0.35; 95%CI = 0.13-0.95), than by smoking only.

CONCLUSIONS

Our findings suggest that multiple modes of use may be an important indicator or risky cannabis use among youth, given associations with frequency, solitary use, and age of onset.

Consumer perceptions of legal cannabis products in Canada, 2019–2021: a repeat cross-sectional study

Background

Consumer perceptions of legal cannabis products may drive willingness to purchase from the illegal or legal market; however, little is known on this topic. The current study examined perceptions of legal products among Canadian cannabis consumers over a 3-year period following federal legalization of non-medical cannabis in 2018.

Methods

Data were analyzed from Canadian respondents in the International Cannabis Policy Study, a repeat cross-sectional survey conducted in 2019–2021. Respondents were 15,311 past 12-month cannabis consumers of legal age to purchase cannabis. Weighted logistic regression models examined the association between perceptions of legal cannabis and province of residence, and frequency of cannabis use over time.

Results

In 2021, cannabis consumers perceived legal cannabis to be safer to buy (54.0%), more convenient to buy (47.8%), more expensive (47.2%), safer to use (46.8%) and higher quality (29.3%) than illegal cannabis. Except for safety of purchasing, consumers had more favourable perceptions of legal cannabis in 2021 than 2019 across all outcomes. For example, consumers had higher odds of perceiving legal cannabis as more convenient to buy in 2021 than 2019 (AOR = 3.09, 95%CI: 2.65,3.60). More frequent consumers had less favourable perceptions of legal cannabis than less frequent consumers.

Conclusions

Three years since legalization, Canadian cannabis consumers generally had increasingly favourable perceptions of legal vs. illegal products – except for price – with variation across the provinces and frequency of cannabis use. To achieve public health objectives of legalization, federal and provincial governments must ensure that legal cannabis products are preferred to illegal, without appealing to non-consumers.

Association of Tetrahydrocannabinol Content and Price in Herbal Cannabis Products Offered by Dispensaries in California: A Purview of Consumers/Patients

Background and Aims

The U.S. legal cannabis market is saturated with products containing high levels of tetrahydrocannabinol (THC), with no distinction between medical and recreational programs. This omnipresence of potent cannabis products seems to be driven by the recreational realm, where cannabis with the highest THC content is prized. This prevalence of highly potent cannabis is conveyed to medical programs, which places consumers (patients) at higher risk for over consumption and cannabis use disorder. Thus, understanding what factors influence the market that patients face in medical cannabis programs could shed light on the risks of legal cannabis. The supply and demand dynamic of the US for-profit cannabis market could explain the current market composition; therefore, we postulate that a financial gain could influence the perpetuation of the prevalence of high THC products in legal cannabis dispensaries. We investigate whether THC content in popular cannabis products correlates with higher prices and assess whether some attributes (type of product, chemovars, or presence of cannabidiol (CBD) affect the association of THC with price.

Methods

We focus on the world's largest cannabis market, California. We randomly selected dispensaries across the state, screened for a web presence and product menu, determined the most prevalent product type, and collected THC and CBD concentration, price, and other product attributes.

Results

We observed that herbal products were more common, they had THC concentrations greater than 10%, and THC concentrations positively correlated with price. This correlation existed in flower and preroll presentations, all chemovar, and independently of the level of CBD. CBD did not correlate with price; however, the presence of CBD diminished the THC and price correlation particularly in products with high THC (&gt;15%).

Conclusions

Overall, highly potent herbal cannabis products (&gt;15% THC) are the majority of products offered and more expensive regardless of product type or chemovar in California dispensaries, suggesting that a financial gain contributes to the current market composition. Efforts to limit the availability of highly potent THC products and educate consumers about potential harms are needed.

Demand curve analysis of marijuana use among persons living with HIV

BACKGROUND

Despite medicalization and legalization of marijuana use, factors influencing demand for marijuana among persons living with HIV (PLWH) are incompletely understood. This knowledge gap undermines effective clinical management and policies. This study used demand curve simulation methods to address these issues.

METHODS

Marijuana-using PLWH (N = 119) completed experimental tasks to simulate amount of marijuana purchasing/use across different costs (money or time), and likelihood of reselling marijuana or marijuana therapeutic-use registration card in relation to profits. Additional simulations assessed purchasing of marijuana relative to other drug and non-drug goods.

RESULTS

Simulated marijuana use decreased as money and time costs increased. Consumption was greater for participants with more severe Cannabis Use Disorder (CUD) and anxiety, intermediate pain levels, and past 90-day opioid use. Whereas few participants chose to sell their registration card, marijuana resale (diversion) steeply increased with profit. Likelihood of seeking marijuana therapeutic-use certification decreased in relation to registration card money cost, having to visit more physicians to get a signature, and delay to receiving the card, and increased with duration of certification. Participants who reported recent opioid use were more likely to seek certification. Consumption of several commodities assessed was independent of marijuana.

CONCLUSIONS

Simulated marijuana use was related to participants' clinical profile (CUD, anxiety and pain symptoms, recent opioid use), and unrelated to purchasing other goods. Likelihood of seeking marijuana therapeutic-use registration was affected by several types of costs and recent opioid use. Participants were unlikely to divert registration cards. We discuss clinical and policy implications of these findings.

Who's Buying What and How Much? Correlates of Purchase Behaviors From Medical Marijuana Dispensaries in Los Angeles, California

Venue-based distribution of marijuana has become the normative model in the United States to obtain marijuana. This study examines one-time purchase behaviors at medical marijuana dispensaries (MMDs) to identify potential venue- and individual-level targets for prevention. We used a two-stage, venue-based sampling approach to randomly select patrons exiting 16 MMDs in Los Angeles, California during the spring of 2013. Patrons (N = 595) reported their discrete purchase behaviors during their most recent visit to the sampled MMD. We used hierarchical linear modeling to examine the amount spent on marijuana products, regressed on characteristics of the sampled dispensaries and their patrons. We used hierarchical generalized linear modeling to examine the likelihood of purchasing specific types of marijuana products and total grams of loose-leaf buds purchased. Patrons spent US$41.73 on average, with a range of $0-$330. We observed significant variation in purchase behaviors across MMDs and associations between venues located within high median income census tracts and a higher total amount spent and lower odds of purchasing only loose-leaf buds. The networked distance between a patron's home and the sampled MMD was positively associated with the total amount spent and total quantity of buds purchased. We also found significant relationships between medical conditions reported for use in three models: total amount spent, purchase of pre-rolled joints, and total grams of buds purchased. Policy makers may want to explore regulating the availability of specialty items that may be attractive to naïve users, such as pre-rolled joints or edibles, or high-concentration products that may be sought out by regular, heavy users.

The impacts of potency, warning messages, and price on preferences for Cannabis flower products

BACKGROUND

Recreational cannabis has been legalized in 11 states and Washington DC in the US. However, little is known about individual preferences for legal cannabis products. This study estimated the impacts of tetrahydrocannabinol (THC), cannabidiol (CBD), warning messages, and price on preferences for cannabis flowers.

METHODS

A cross-sectional online survey with discrete choice experiments was implemented in October 2017. A sample of 2400 adults aged 21 years or older were recruited from 6 US states with recreational cannabis legalization, consisting of 1200 past-year nonusers and 1200 past-year users. Each respondent was randomly assigned to 12 discrete choice scenarios, each asking them to choose from an opt-out option and 3 cannabis flower products with varying levels in THC, CBD, warning messages, and price. The impacts of product attributes on individual choices were analyzed with nested logit regressions.

RESULTS

Both cannabis nonusers and users preferred higher CBD and lower price. Users also preferred higher THC. The results on warning messages were mixed: graphic warning on drugged driving and text warning message had positive impacts on nonusers' and users' preferences for cannabis flowers, respectively, whereas FDA disapproval disclaimer had negative impacts on nonusers' preferences. Heterogeneities in preferences were revealed among nonusers by former use status and among users by reason of use. Particularly, medical cannabis users were not as responsive to THC as recreational cannabis users or dual users were. Regarding relative importance of the attributes, all respondents but medical cannabis users perceived price as the most important attribute (relative importance 51-64%), whereas medical cannabis users perceived CBD as the most important attribute (relative importance 47%).

CONCLUSION

The findings indicated that product characteristics may have influences on US adults' choices of legal cannabis flower products and may deserve consideration for cannabis regulatory framework.

Tobacco and cannabis co-use: Drug substitution, quit interest, and cessation preferences

The co-use of tobacco and cannabis is a common practice worldwide and carries with it substantial public health burden. Few interventions exist that target both substances and little is known about quit interest, treatment preferences, and drug substitution during past cessation attempts, which is critical to guide the development of treatment strategies. The goal of this study was to provide descriptive information regarding quit interest, treatment preferences, and perceived drug substitution among adult (age 18 +) cannabis-tobacco co-users. Participants (N = 282) from two independent survey samples (recruited from Amazon Mechanical Turk) from across the United States were combined. Among all participants, 57% were female, 79% were White, and average age was 33.31 (SD = 9.54) years old. Approximately 80% had tried to quit smoking cigarettes at least once, while 40% had tried to quit using cannabis at least once. Of those who tried to quit, 50% self-reported a perceived increase in their cannabis use during tobacco cessation and 62% self-reported a perceived increase in their tobacco use during cannabis cessation. Average quit interest (10-point scale) for cannabis was 2.39 (SD = 2.35) and for tobacco was 7.07 (SD = 2.90). Results of this study suggest that tobacco use should be addressed among cannabis-tobacco co-users, but interventions should consider lack of interest in cannabis cessation. Reduction-based strategies for cannabis use appear to be more acceptable to this nontreatment-seeking, co-using population. Drug substitution during quit attempts for one substance should be further explored as an important treatment consideration. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Medical Marijuana Availability, Price, and Product Variety, and Adolescents' Marijuana Use

PURPOSE

We aimed to examine the availability of medical marijuana dispensaries, price of medical marijuana products, and variety of medical marijuana products in school neighborhoods and their associations with adolescents' use of marijuana and susceptibility to use marijuana in the future.

METHODS

A representative sample of 8th, 10th, and 12th graders (N = 46,646) from 117 randomly selected schools in California participated in the cross-sectional 2015-2016 California Student Tobacco Survey (CSTS). Characteristics of medical marijuana dispensaries in California were collected and combined with school locations to compute availability, price, and product variety of medical marijuana in school neighborhoods. Multilevel logistic regressions with random intercepts at school level were conducted to test the associations, accounting for individual and school socioeconomic characteristics.

RESULTS

The distance from school to the nearest medical marijuana dispensary (within 0- to 1-mi and 1- to 3-mi bands) was not associated with adolescents' use of marijuana in the past month or susceptibility to use marijuana in the future, nor was the weighted count of medical marijuana dispensaries within the 3-mi band of school. Neither the product price nor the product variety in the dispensary nearest to school was associated with marijuana use or susceptibility to use. The results were robust to different specifications of medical marijuana measures.

CONCLUSIONS

There was no evidence supporting the associations of medical marijuana availability, price, or product variety around school with adolescents' marijuana use and susceptibility to use.

Studying Cannabis Use Behaviors With Facebook and Web Surveys: Methods and Insights

The rapid and wide-reaching expansion of internet access and digital technologies offers epidemiologists numerous opportunities to study health behaviors. One particularly promising new data collection strategy is the use of Facebook’s advertising platform in conjunction with Web-based surveys. Our research team at the Center for Technology and Behavioral Health has used this quick and cost-efficient method to recruit large samples and address unique scientific questions related to cannabis use. In conducting this research, we have gleaned several insights for using this sampling method effectively and have begun to document the characteristics of the resulting data. We believe this information could be useful to other researchers attempting to study cannabis use or, potentially, other health behaviors. The first aim of this paper is to describe case examples of procedures for using Facebook as a survey sampling method for studying cannabis use. We then present several distinctive features of the data produced using this method. Finally, we discuss the utility of this sampling method for addressing specific types of epidemiological research questions. Overall, we believe that sampling with Facebook advertisements and Web surveys is best conceptualized as a targeted, nonprobability-based method for oversampling cannabis users across the United States.

Big data on a big new market: Insights from Washington State's legal cannabis market

INTRODUCTION

Voters in eight U.S. states have passed initiatives to legalize large-scale commercial production of cannabis for non-medical use. All plan or require some form of "seed-to-sale" tracking systems, which provide a view of cannabis market activity at a heretofore unimagined level of detail. Legal markets also create a range of new matters for policy makers to address.

DATA

Publicly available data were obtained on approximately 45 million individually priced items purchased in the 35 million retail transactions that took place during the first two and a half years of Washington State's legal cannabis market. Records include product type (flower, extract, lotion, liquid edible, etc.), product name, price, and potency with respect to multiple cannabinoids, notably THC and CBD. Items sold can be traced back up the supply chain through the store to the processor and producer, to the level of identifying the specific production batch and mother plant, the firm that tested the product, and test results.

METHOD

Data visualization methods are employed to describe spatial-temporal patterns of multiple correlated attributes (e.g., price and potency) broken down by product. Text-analytic methods are used to subdivide the broad category of "extracts for inhalation" into more homogeneous sub-categories. To understand the competitiveness of the legal cannabis market in Washington we calculate the Herfindahl-Hirschman index (HHI) for processors and retailers.

RESULTS

Cannabis prices fell steadily and proportionally at the processor and retailer levels. Retail and wholesale price maintained a roughly 3:1 ratio for multiple product types after some initial fluctuations. Although a wide range of edibles are sold, they account for a modest share of consumer spending; extracts for inhalation are a larger and heterogeneous market segment. The HHI indicates the cannabis market is highly competitive at the processor level, but less so for retail markets at the county level.

CONCLUSIONS

Washington's state-legal cannabis market is diverse and rapidly evolving in terms of pricing, products, and organization. Post-legalization, researchers and policy makers may need to think in terms of a family of cannabis products, akin to how we think of new psychoactive substances and amphetamine-type stimulants, not a single drug "cannabis."

Early Impacts of Marijuana Legalization: An Evaluation of Prices in Colorado and Washington

Following the legalization and regulation of marijuana for recreational purposes in states with medical markets, policymakers and researchers seek empirical evidence on how, and how fast, supply and demand changed over time. Prices are an indication of how suppliers and consumers respond to policy changes, so this study uses a difference-in-difference approach to exploit the timing of policy implementation and identify the impacts on marijuana prices 4-5 months after markets opened. This study uses unique longitudinal survey data of prices paid by consumers and a web-scraped dataset of dispensary prices advertised online for three U.S. medical marijuana states that all eventually legalized recreational marijuana. Results indicate there were no impacts on the prices paid for medical or recreational marijuana by state-representative residents within the short 4- to 5-months window following legalization. However, there were differences in how much people paid if they obtained marijuana for recreational purposes from a recreational store. Further analysis of advertised prices confirms this result, but further demonstrates heterogeneous responses in prices across types of commonly advertised strains; prices either did not change or increased depending on the strain type. A key implication of our findings is that there are both supply and demand responses at work in the opening of legalized markets, suggesting that evaluations of immediate effects may not accurately reflect the long run impact of legalization on consumption.

Medical Marijuana and Marijuana Legalization

State-level marijuana liberalization policies have been evolving for the past five decades, and yet the overall scientific evidence of the impact of these policies is widely believed to be inconclusive. In this review we summarize some of the key limitations of the studies evaluating the effects of decriminalization and medical marijuana laws on marijuana use, highlighting their inconsistencies in terms of the heterogeneity of policies, the timing of the evaluations, and the measures of use being considered. We suggest that the heterogeneity in the responsiveness of different populations to particular laws is important for interpreting the mixed findings from the literature, and we highlight the limitations of the existing literature in providing clear insights into the probable effects of marijuana legalization.

Medicinal versus Recreational Cannabis Use among Returning Veterans

BACKGROUND

Although increasing rates of cannabis use and cannabis use disorder (CUD) are well-documented among veterans, little is known about their use of cannabis specifically for medicinal purposes. The present study characterizes such use and compares veterans reporting cannabis use for medicinal (n = 66) versus recreational (n = 77) purposes on (a) sociodemographic factors, (b) psychiatric disorders (posttraumatic stress disorder [PTSD], major depressive disorder [MDD], and CUD), (c) other substance use, (d) reasons for cannabis use and cannabis-related problems, and (e) physical and mental health.

METHODS

Participants were veterans deployed post 9/11/2001 recruited from a Veterans Health Administration (VHA) facility (N = 143; mean [SD] age = 30.0 [6.6]; mean [SD] deployments = 1.7 [1.1]) who reported past-year cannabis use.

RESULTS

The most frequently endorsed conditions for medicinal cannabis (MC) use were anxiety/stress, PTSD, pain, depression, and insomnia. In logistic regression analyses adjusted for frequency of cannabis use, MC users were significantly more likely (OR = 3.16) to meet criteria for PTSD than recreational cannabis (RC) users. Relative to RC users, MC users reported significantly greater motivation for using cannabis to cope with sleep disturbance as well as significantly poorer sleep quality and worse physical health.

CONCLUSIONS

Veterans who use cannabis for medicinal purposes differ significantly in sleep, physical and mental health functioning than veterans who use cannabis for recreational purposes. PTSD and sleep problems may be especially relevant issues to address in screening and providing clinical care to returning veterans who are using cannabis for medicinal purposes.

"Maturing Out" of Binge and Problem Drinking

This article reviews literature aiming to explain the widespread reductions in binge and problem drinking that begin around the transition to young adulthood (i.e., "maturing out"). Whereas most existing literature on maturing out emphasizes contextual effects of transitions into adult roles and responsibilities, this article also reviews recent work demonstrating further effects of young adult personality maturation. As possible mechanisms of naturally occurring desistance, these processes could inform both public health and clinical interventions aimed at spurring similar types of drinking-related behavior change. This article also draws attention to evidence that the normative trend of age-related reductions in problem drinking extends well beyond young adulthood. Specific factors that may be particularly relevant to problem drinking desistance in these later periods are considered within a broader life span developmental framework.

The potential impact of cannabis legalization on the development of cannabis use disorders

Specific provisions of legal cannabis legislation and regulation could influence cannabis initiation, frequency and quantity of use, and progression to cannabis use disorder. This brief essay highlights scientifically based principles and risk factors that underlie substance use and addiction that can be leveraged to inform policies that might mitigate the development and consequences of cannabis use disorder. Specifically, pharmacologic, access/availability, and environmental factors are discussed in relation to their influence on substance use disorders to illustrate how regulatory provisions can differentially affect these factors and risk for addiction. Relevant knowledge from research and experience with alcohol and tobacco regulation are also considered. Research designed to inform regulatory policy and to evaluate the impact of cannabis legislation on cannabis use and problems is progressing. However, definitive findings will come slowly, and more concerted efforts and resources are needed to expedite this process. In the meantime, policymakers should take advantage of the large body of scientific literature on substance use to foster empirically-guided, common sense approaches to cannabis policy that focus on prevention of addiction.

How Medical Marijuana Smoothed the Transition to Marijuana Legalization in the United States

Public support for legalizing marijuana use increased from 25% in 1995 to 60% in 2016, rising in lockstep with support for same-sex marriage. Between November 2012 and November 2016, voters in eight states passed ballot initiatives to legalize marijuana sales for nonmedical purposes-covering one-fifth of the US population. These changes are unprecedented but are not independent of the changes in medical marijuana laws that have occurred over the past 20 years. This article suggests five ways in which the passage and implementation of medical marijuana laws smoothed the transition to nonmedical legalization in the United States: (a) They demonstrated the efficacy of using voter initiatives to change marijuana supply laws, (b) enabled the psychological changes needed to destabilize the "war on drugs" policy stasis, (c) generated an evidence base that could be used to downplay concerns about nonmedical legalization, (d) created a visible and active marijuana industry, and (e) revealed that the federal government would allow state and local jurisdictions to generate tax revenue from marijuana.

Understanding and learning from the diversification of cannabis supply laws

BACKGROUND AND AIMS

Prohibitions on producing, distributing and selling cannabis are loosening in various jurisdictions around the world. This paper describes the diversification of cannabis supply laws and discusses the challenges to and opportunities for learning from these changes.

METHODS

We document changes in cannabis supply laws that de jure legalized cannabis production for medical and/or non-medical purposes (excluding industrial hemp) in Australasia, Europe, North America and South America. We also highlight challenges to evaluating these legal changes based on our experiences studying cannabis laws and policies in the United States.

FINDINGS

As of August 2016, two countries have passed laws to legalize large-scale cannabis production for non-medical purposes at the national (Uruguay) or subnational level (four US states). At least nine other countries legally allow (or will soon allow) cannabis to be supplied for medicinal purposes. Most of the changes in cannabis supply laws have occurred since 2010. The data available in most countries are inadequate for rigorously evaluating the changes in cannabis supply laws.

CONCLUSION

The evidence base for assessing changes in cannabis supply laws remains weak. Efforts should focus upon collecting information about quantities consumed and market transactions as well as validating self-report surveys.

The effects of perceived quality on behavioral economic demand for marijuana: A web-based experiment

BACKGROUND

Given the growing legalization of recreational marijuana use and related increase in its prevalence in the United States, it is important to understand marijuana's appeal. We used a behavioral economic (BE) approach to examine whether the reinforcing properties of marijuana, including "demand" for marijuana, varied as a function of its perceived quality.

METHODS

Using an innovative, Web-based marijuana purchase task (MPT), a sample of 683 young-adult recreational marijuana users made hypothetical purchases of marijuana across three qualities (low, mid and high grade) at nine escalating prices per joint, ranging from $0/free to $20.

RESULTS

We used nonlinear mixed effects modeling to conduct demand curve analyses, which produced separate demand indices (e.g., P_max, elasticity) for each grade of marijuana. Consistent with previous research, as the price of marijuana increased, marijuana users reduced their purchasing. Demand also was sensitive to quality, with users willing to pay more for higher quality/grade marijuana. In regression analyses, demand indices accounted for significant variance in typical marijuana use.

CONCLUSIONS

This study illustrates the value of applying BE theory to young adult marijuana use. It extends past research by examining how perceived quality affects demand for marijuana and provides support for the validity of a Web-based MPT to examine the appeal of marijuana. Our results have implications for policies to regulate marijuana use, including taxation based on the quality of different marijuana products.

State and National Contexts in Evaluating Cannabis Laws: A Case Study of Washington State

As of January 2016, 23 U.S. states and the District of Columbia have legalized medical or nonmedical cannabis, with more likely to follow. This dynamic policy context represents a substantial challenge for policy evaluation. Part I of this article provides a summary of state-level cannabis policy components across states and federal action regarding state-level policies. Part II presents a detailed history of cannabis policies in Washington State from 1998 to 2015 and analyzes the potential impacts of the policy changes on cannabis supply and demand. As an early adopter of both medical and nonmedical cannabis policies, Washington State provides an excellent example of the key elements to be considered in evaluating the relationship between policy changes and cannabis use. We highlight the importance of the interplay of federal enforcement priorities and previously adopted state-level cannabis regimes in interpreting the potential impacts of new cannabis policies.

Do consumers substitute opium for hashish? An economic analysis of simultaneous cannabinoid and opiate consumption in a legal regime

AIM

To analyze interrelationships in the consumption of opiates and cannabinoids in a legal regime and, specifically, whether consumers of opiates and cannabinoids treat them as substitutes for each other.

METHOD

Econometric dynamic panel data models for opium consumption are estimated using the generalized method of moments (GMM). A unique dataset containing information about opiate (opium) consumption from the Punjab province of British India for the years 1907-1918 is analyzed (n=252) as a function of its own price, the prices of two forms of cannabis (the leaf (bhang), and the resin (charas, or hashish)), and wage income. Cross-price elasticities are examined to reveal substitution or complementarity between opium and cannabis.

RESULTS

Opium is a substitute for charas (or hashish), with a cross price elasticity (βˆ3) of 0.14 (p<0.05), but not for bhang (cannabis leaves; cross price elasticity=0.00, p>0.10). Opium consumption (βˆ1=0.47 to 0.49, p<0.01) shows properties of habit persistence consistent with addiction. The consumption of opium is slightly responsive (inelastic) to changes in its own price (βˆ2=-0.34 to -0.35, p<0.05 to 0.01) and consumer wages (βˆ1=0.15, p<0.05).

CONCLUSION

Opium and hashish, a form of cannabis, are substitutes. In addition, opium consumption displays properties of habit persistence and slight price and wage income responsiveness (inelasticity) consistent with an addictive substance.