Riding the waves from epidemic to endemic: Viral mutations, immunological change and policy responses

Nonpharmaceutical interventions (NPI) are an important tool for countering pandemics such as COVID-19. Some are cheap; others disrupt economic, educational, and social activity. The latter force governments to balance the health benefits of reduced infection and death against broader lockdown-induced societal costs. A literature has developed modeling how to optimally adjust lockdown intensity as an epidemic evolves. This paper extends that literature by augmenting the classic SIR model with additional states and flows capturing decay over time in vaccine-conferred immunity, the possibility that mutations create variants that erode immunity, and that protection against infection erodes faster than protecting against severe illness. As in past models, we find that small changes in parameter values can tip the optimal response between very different solutions, but the extensions considered here create new types of solutions. In some instances, it can be optimal to incur perpetual epidemic waves even if the uncontrolled infection prevalence would settle down to a stable intermediate level.

The Baltic and Nordic responses to the first Taliban poppy ban: Implications for Europe & synthetic opioids today

The 2000-2001 and the 2022-2023 Taliban opium bans were and could be two of the largest ever disruptions to a major illegal drug market. To help understand potential implications of the current ban for Europe, this paper analyzes how opioid markets in seven Baltic and Nordic countries responded to the earlier ban, using literature review, key informant interviews, and secondary data analysis. The seven nations' markets responded in diverse ways, including rebounding with the same drug (heroin in Norway), substitution to a more potent opioid (fentanyl replacing heroin in Estonia), and substitution to one with lower risk of overdose (buprenorphine replacing heroin in Finland). The responses were not instantaneous, but rather evolved, sometimes over several years. This variety suggests that it can be hard to predict how drug markets will respond to disruptions, but two extreme views can be challenged. It would be naive to imagine that drug markets will not adapt to shocks, but also unduly nihilistic to presume that they will always just bounce back with no lasting effects. Substitution to another way of meeting demand is possible, but that does not always negate fully the benefits of disrupting the original market. Nonetheless, there is historical precedent for a European country's opioid market switching to synthetic opioids when heroin supplies were disrupted. Given how much that switch has increased overdose rates in Canada and the United States, that is a serious concern for Europe at present. A period of reduced opioid supply may be a particularly propitious time to expand treatment services (as Norway did in the early 2000s).

The hammer and the jab: Are COVID-19 lockdowns and vaccinations complements or substitutes?

The COVID-19 pandemic has devastated lives and economies around the world. Initially a primary response was locking down parts of the economy to reduce social interactions and, hence, the virus' spread. After vaccines have been developed and produced in sufficient quantity, they can largely replace broad lock downs. This paper explores how lockdown policies should be varied during the year or so gap between when a vaccine is approved and when all who wish have been vaccinated. Are vaccines and lockdowns substitutes during that crucial time, in the sense that lockdowns should be reduced as vaccination rates rise? Or might they be complementary with the prospect of imminent vaccination increasing the value of stricter lockdowns, since hospitalization and death averted then may be permanently prevented, not just delayed? We investigate this question with a simple dynamic optimization model that captures both epidemiological and economic considerations. In this model, increasing the rate of vaccine deployment may increase or reduce the optimal total lockdown intensity and duration, depending on the values of other model parameters. That vaccines and lockdowns can act as either substitutes or complements even in a relatively simple model casts doubt on whether in more complicated models or the real world one should expect them to always be just one or the other. Within our model, for parameter values reflecting conditions in developed countries, the typical finding is to ease lockdown intensity gradually after substantial shares of the population have been vaccinated, but other strategies can be optimal for other parameter values. Reserving vaccines for those who have not yet been infected barely outperforms simpler strategies that ignore prior infection status. For certain parameter combinations, there are instances in which two quite different policies can perform equally well, and sometimes very small increases in vaccine capacity can tip the optimal solution to one that involves much longer and more intense lockdowns.

Modeling cartel size to inform violence reduction in Mexico

Estimating stocks and flows is an innovative first step.

Changing dynamics of drug overdoses in the United Kingdom: An attempt to replicate the Jalal et al. findings of steady exponential growth

BACKGROUND

Jalal et al. discovered that between 1979 and 2020 total rates and counts of fatal drug overdoses in the United States exhibited exponential growth at a very steady rate even though deaths from individual drugs did not. That is a startling result because it means that the different drugs are in effect "taking turns", with one growing faster just as another drug's death rate growth ebbs. That raises the question of whether this steadiness in the all-drug death rates is in some sense just a coincidence peculiar to the United States or whether it might reflect some more general phenomenon and so manifest in other countries.

METHODS

We fit the same model used by Jalal et al. to data on drug-related death rates for the countries of the United Kingdom.

RESULTS

The main finding is largely a failure to replicate the United States result. Simple graphical display of the trends and a number of statistical measures show that the growth in the United Kingdom was not only slower than in the United States, it was also less steady, with the exception of Northern Ireland.

CONCLUSIONS

Steady exponential growth in the all-drugs mortality rate may be a phenomenon specific to certain contexts. It remains an open question whether the explanation of steady exponential growth in the United States and Northern Ireland relates to demand and supply mechanisms, to social and political conditions, or to coincidence.

America's Opioid Ecosystem: How Leveraging System Interactions Can Help Curb Addiction, Overdose, and Other Harms

Opioids play an outsized role in America's drug problems, but they also play a critically important role in medicine. Thus, they deserve special attention. Illegally manufactured opioids (such as fentanyl) are involved in a majority of U.S. drug overdoses, but the problems are broader and deeper than drug fatalities. Depending on the drugs involved, there can be myriad physical and mental health consequences associated with having a substance use disorder. And it is not just those using drugs who suffer. Substance use and related behaviors can significantly affect individuals' families, friends, employers, and wider communities. Efforts to address problems related to opioids are insufficient and sometimes contradictory. Researchers provide a nuanced assessment of America's opioid ecosystem, highlighting how leveraging system interactions can reduce addiction, overdose, suffering, and other harms. At the core of the opioid ecosystem are the individuals who use opioids and their families. Researchers also include detail on ten major components of the opioid ecosystem: substance use disorder treatment, harm reduction, medical care, the criminal legal system, illegal supply and supply control, first responders, the child welfare system, income support and homeless services, employment, and education. The primary audience for this study is policymakers, but it should also be useful for foundations looking for opportunities to create change that have often been overlooked. This study can help researchers better consider the full consequences of policy changes and help members of the media identify the dynamics of interactions that deserve more attention.

When prohibition works: Comparing fireworks and cannabis regulations, markets, and harms

BACKGROUND

Nations wrestle with whether to prohibit products that can harm consumers and third parties but whose prohibition creates illegal markets. For example, cannabis is banned in most of the world, but supply for non-medical use has been legalized in Uruguay, Canada, and much of the United States and possession restrictions have been liberalized in other countries. Likewise, supply and possession of fireworks have been subject to varying degrees of prohibition in multiple countries, with those bans prompting significant evasion.

METHODS

Current and past history of fireworks regulations, sales, and harms are reviewed and contrasted with those for cannabis. The focus is on the United States, but literature from other countries is incorporated when possible and appropriate. This extends the insightful literature comparing drugs to other vices (such as gambling and prostitution) by comparing a drug to a risky pleasure that is not seen as a vice but which has been subject to prohibition.

RESULTS

There are many parallels between fireworks and cannabis in legal approaches, harms to "users", harms to others, and other externalities. In the U.S. the timing of prohibitions were similar, with prohibitions on fireworks being imposed a little later and repealed a little sooner. Internationally, the countries that are strictest with fireworks are not always those that are strictest with drugs. By some measures, harms are of roughly similar magnitude. During the last years of U.S. cannabis prohibition, there were about 10 emergency department (ED) events per million dollars spent on both fireworks and illegal cannabis, but fireworks generated very roughly three times as many ED events per hour of use/enjoyment. There are also differences, e.g., punishments were less harsh for violating fireworks prohibitions, fireworks consumption is heavily concentrated in just a few days or weeks per year, and illegal distribution is primarily of diverted legal products, not of illegally produced materials.

CONCLUSIONS

The absence of hysteria over fireworks problems and policies suggests that societies can address complex tradeoffs involving risky pleasures without excessive acrimony or divisiveness when that product or activity is not construed as a vice. However, the conflicted and time-varying history of fireworks bans also show that difficulty balancing freedoms and pleasure with harms to users and others is not restricted to drugs or other vices. Use-related harms fell when fireworks were banned and rose when those bans were repealed, so fireworks prohibitions can be seen as "working" from a public health perspective, but not well enough for bans to be employed in all times or places.

Rapid changes in illegally manufactured fentanyl products and prices in the United States

BACKGROUND AND AIMS

Synthetic opioids, mostly illegally manufactured fentanyl (IMF), were mentioned in 60% of United States (US) drug overdose deaths in 2020, with dramatic variation across states that mirrors variation in IMF supply. However, little is known about IMF markets in the United States and how they are changing. Researchers have previously used data from undercover cocaine, heroin, and methamphetamine purchases and seizures to examine how their use and related harms respond to changes in price and availability. This analysis used US Drug Enforcement Administration (DEA) data to address two questions: (i) "To what extent does IMF supply vary over time and geography?" and (ii) "What has happened to the purity-adjusted price of IMF?"

METHODS

We developed descriptive statistics and visualizations using data from 66 713 observations mentioning IMF and/or heroin from the DEA's System to Retrieve Information from Drug Evidence (STRIDE; now STARLIMS) from 2013 to 2021. Price regressions were estimated with city-level fixed effects examining IMF-only powder observations with purity and price information at the low-to-medium wholesale level (>1 g to ≤100 g; n = 964).

RESULTS

From 2013 to 2021, the share of heroin and/or IMF observations mentioning IMF grew from near zero to more than two-thirds. The share of heroin observations also containing IMF grew from <1% to ~40%. There is important geographic variation: in California, most IMF seizures involved counterfeit tablets, whereas New York and Massachusetts largely involved powder formulation. The median price per pure gram of IMF powder sold at the >10 to ≤100 g level fell by more than 50% from 2016 to 2021; regression analyses suggested an average annual decline of 17% (P < 0.001). However, this price decline appears to have been driven by observations from the Northeast.

CONCLUSIONS

Since 2013, the illegally manufactured fentanyl problem in the United States has become more deadly and more diverse.

How much illegally manufactured fentanyl could the U.S. be consuming?

The spread of illegally manufactured opioids, including fentanyl, has brought unprecedented levels of drug overdose deaths in North America. In some markets, illegally manufactured fentanyl (IMF) is essentially displacing heroin, not just being used to adulterate it. It is not possible at this time to provide an accurate point estimate of the amount of IMF consumed in the United States. Yet for various purposes (e.g. assessing changes in production levels and the appropriate role for various supply reduction efforts), it is important to have a sense of scale. This article provides guidance through two thought experiments that provide a hypothetical upper bound on U.S. consumption. The first considers a scenario in which IMF replaces heroin in all illegal opioid markets. The second starts with the number of individuals with an opioid use disorder and considers what total consumption would be if IMF was the only opioid they consumed. Both calculations suggest it is unlikely that the annual consumption of IMF in 2021 could have been more than single digit pure metric tons. For comparison, the most recent best estimates of the amount of cocaine and heroin consumed in the U.S. are 145 and 47 pure metric tons, respectively. The article also raises questions about the limitations of using traditional equianalgesic morphine equivalent dose conversions to estimate the total market consumption of IMF.

The International Cannabis Toolkit (iCannToolkit): a multidisciplinary expert consensus on minimum standards for measuring cannabis use

BACKGROUND

The lack of an agreed international minimum approach to measuring cannabis use hinders the integration of multidisciplinary evidence on the psychosocial, neurocognitive, clinical and public health consequences of cannabis use.

METHODS

A group of 25 international expert cannabis researchers convened to discuss a multidisciplinary framework for minimum standards to measure cannabis use globally in diverse settings.

RESULTS

The expert-based consensus agreed upon a three-layered hierarchical framework. Each layer-universal measures, detailed self-report and biological measures-reflected different research priorities and minimum standards, costs and ease of implementation. Additional work is needed to develop valid and precise assessments.

CONCLUSIONS

Consistent use of the proposed framework across research, public health, clinical practice and medical settings would facilitate harmonisation of international evidence on cannabis consumption, related harms and approaches to their mitigation.

How much demand for money laundering services does drug selling create? Identifying the key parameters

BACKGROUND

The illegal drug trade is often, and plausibly, asserted to be the largest illegal market, globally and in many individual countries. It is also claimed that a large share of its revenues is laundered, though there are no estimates of that volume. We provide rough estimates of that proportion and its primary determinants.

METHODS AND DATA

This paper presents a model of a multi-tiered drug distribution network that is parameterized with data based on one typical, well-studied case, namely British Colombia's market for illegal opioids, supplemented by a corresponding economic interpretation of what determines the share of drug trade revenues that need to be laundered. Sensitivity with respect to key parameters is analyzed.

FINDINGS

We suggest that less than half and perhaps no more than a quarter of revenues from established drug markets need laundering. Key parameters governing this proportion include the price mark-up across distribution levels, transaction volumes at each market level, and the capacity of market participants to spend cash on daily living expenses.

CONCLUSION

This model permits estimation of the scale of money laundering associated with a particular drug market. It suggests that there are limits on money laundering controls as a way of reducing drug supply - although money laundering investigations may still be an effective way to identify and investigate high-level drug traffickers.

Heroin use cannot be measured adequately with a general population survey

BACKGROUND

Globally, heroin and other opioids account for more than half of deaths and years-of-life-lost due to drug use and comprise one of the four major markets for illegal drugs. Having sound estimates of the number of problematic heroin users is fundamental to formulating sound health and criminal justice policies. Researchers and policymakers rely heavily upon general population surveys (GPS), such as the US National Survey on Drug Use and Health (NSDUH), to estimate heroin use, without confronting their limitations. GPS-based estimates are also ubiquitous for cocaine and methamphetamine, so insights pertaining to GPS for estimating heroin use are also relevant for those drug markets.

ANALYSIS

Four sources of potential errors in NSDUH are assessed: selective non-response, small sample size, sampling frame omissions and under-reporting. An alternative estimate drawing on a variety of sources including a survey of adult male arrestees is presented and explained. Other approaches to prevalence estimation are discussed.

FINDINGS

Under-reporting and selective non-response in NSDUH are likely to lead to substantial underestimation. Small sample size leads to imprecise estimates and erratic year-to-year fluctuations. The alternative estimate provides credible evidence that NSDUH underestimates the number of frequent heroin users by at least three-quarters and perhaps much more.

IMPLICATIONS

GPS, even those as strong as NSDUH, are doomed by their nature to estimate poorly a rare and stigmatized behavior concentrated in a hard-to-track population. Although many European nations avoid reliance upon these surveys, many others follow the US model. Better estimation requires models that draw upon a variety of data sources, including GPS, to provide credible estimates. Recent methodological developments in selected countries can provide guidance. Journals should require researchers to critically assess the soundness of GPS estimates for any stigmatized drug-related behaviors with low prevalence rates.

Community perspectives on supervised consumption sites: Insights from four U.S. counties deeply affected by opioids

BACKGROUND

To address the overdose crisis in the United States, expert groups have been nearly unanimous in calls for increasing access to evidence-based treatment and overdose reversal drugs. In some places there have also been calls for implementing supervised consumption sites (SCSs). Some cities-primarily in coastal urban areas-have explored the feasibility and acceptability of introducing them. However, the perspectives of community stakeholders from more inland and rural areas that have also been hard hit by opioids are largely missing from the literature.

METHODS

To examine community attitudes about implementing SCSs for people who use opioids (PWUO) in areas with acute opioid problems, the research team conducted in-depth interviews and focus groups in four counties: Ashtabula and Cuyahoga Counties in Ohio, and Carroll and Hillsborough Counties in New Hampshire, two states with high rates of opioid overdose. Participants were policy, treatment, and criminal justice professionals, frontline harm reduction and service providers, and PWUO.

RESULTS

Key informants noted benefits to SCSs, but also perceived potential drawbacks such as that they may enable opioid use, and potential practical barriers, including lack of desire among PWUO to travel to an SCS after purchasing opioids and fear of arrest. Key informants generally believed their communities likely would not currently accept SCSs due to cultural, resource, and practical barriers. They viewed publication of evidence on SCSs and community education as essential for fostering acceptance.

CONCLUSIONS

Despite cultural and other barriers, implementation of SCSs may be more feasible in urban communities with existing (and perhaps more long-standing) harm reduction programs, greater treatment resources, and adequate transportation, particularly if there is strong evidence to support them.

The optimal lockdown intensity for COVID-19

One of the principal ways nations are responding to the COVID-19 pandemic is by locking down portions of their economies to reduce infectious spread. This is expensive in terms of lost jobs, lost economic productivity, and lost freedoms. So it is of interest to ask: What is the optimal intensity with which to lockdown, and how should that intensity vary dynamically over the course of an epidemic? This paper explores such questions with an optimal control model that recognizes the particular risks when infection rates surge beyond the healthcare system's capacity to deliver appropriate care. The analysis shows that four broad strategies emerge, ranging from brief lockdowns that only "smooth the curve" to sustained lockdowns that prevent infections from spiking beyond the healthcare system's capacity. Within this model, it can be optimal to have two separate periods of locking down, so returning to a lockdown after initial restrictions have been lifted is not necessarily a sign of failure. Relatively small changes in judgments about how to balance health and economic harms can alter dramatically which strategy prevails. Indeed, there are constellations of parameters for which two or even three of these distinct strategies can all perform equally well for the same set of initial conditions; these correspond to so-called triple Skiba points. The performance of trajectories can be highly nonlinear in the state variables, such that for various times t , the optimal unemployment rate could be low, medium, or high, but not anywhere in between. These complex dynamics emerge naturally from modeling the COVID-19 epidemic and suggest a degree of humility in policy debates. Even people who share a common understanding of the problem's economics and epidemiology can prefer dramatically different policies. Conversely, favoring very different policies is not evident that there are fundamental disagreements.

Intensity of cannabis use: Findings from three online surveys

BACKGROUND

Drug use is often measured in terms of prevalence, meaning the number of people who used any amount in the last month or year, but measuring the quantity consumed is critical for making informed regulatory decisions and estimating the effects of policy changes. Quantity is the product of frequency (e.g., number of use days in the last month) and intensity (amount consumed per use day). Presently, there is imperfect understanding of the extent to which more frequent users also consume more intensively.

METHODS AND DATA

We examine cannabis flower consumption reported in three similar online surveys fielded in times and places where cannabis was and was not legal. These convenience samples returned enough valid responses (n = 2,618) to examine consumption across different frequencies of use via analyses of measures of central tendency, data visualizations, and multivariate regressions. Additional calculations incorporate data from the National Survey on Drug Use and Health.

FINDINGS

Respondents who reported using daily (i.e., 30 days in the past month) consumed almost twice as much per day of use on average as did those reporting less than daily. We find only modest increases in intensity among those using less than daily, but then a substantial increase (p< 0.001) for those who use daily. Most respondents report that on heavy or light use days their consumption differs from a typical day of use by a factor of 2 or more, but only about 25% of days were described as heavy or light. We estimate those using cannabis 21+ days a month account for 80% of consumption vs. 71% of the days of use.

DISCUSSION

Daily cannabis users consume more intensively than others, including near-daily users. When possible, survey questions should move beyond the presence or absence of use and number of days used.

Supervised consumption sites: a nuanced assessment of the causal evidence

BACKGROUND AND AIMS

Supervised consumption sites (SCS) operate in more than 10 countries. SCS have mostly emerged as a bottom-up response to crises, first to HIV/AIDS and now overdose deaths, in ways that make rigorous evaluation difficult. Opinions vary about how much favorable evidence must accumulate before implementation. Our aim was to assess the nature and quality of evidence on the consequences of implementing SCS.

METHODS

We reviewed the higher-quality SCS literature, focusing on articles evaluating natural experiments and mathematical modeling studies that estimate costs and benefits. We discuss the evidence through the lens of three types of decision-makers and from three intellectual perspectives.

RESULTS

Millions of drug use episodes have been supervised at SCS with no reported overdose deaths; however, uncertainties remain concerning the magnitude of the population-level effects. The published literature on SCS is large and almost unanimous in its support, but limited in nature and the number of sites evaluated. It can also overlook four key distinctions: (1) between outcomes that occur within the facility and possible spillover effects on behavior outside the SCS; (2) between effects of supervising consumption and the effects of other services offered, such as syringe or naloxone distribution; (3) between association and causation; and (4) between effectiveness and the cost-effectiveness of SCS compared to other interventions.

CONCLUSIONS

The causal evidence for favorable outcomes of supervised consumption sites is minimal, but there appears to be little basis for concern about adverse effects. This raises the question of how context and priors can affect how high the bar is set when deciding whether to endorse supervised consumption sites. The literature also understates distinctions and nuances that need to be appreciated to gain a rich understanding of how a range of stakeholders should interpret and apply that evidence to a variety of decisions.

Prescribing diamorphine in the United States: Insights from a nationally representative survey

BACKGROUND

Some countries allow physicians to prescribe pharmaceutical-grade diamorphine to dependent users who have previously undergone treatment but are still using street-sourced heroin; this is not allowed in the US. This study provides the first nationally representative US data concerning public support for prescribing diamorphine to dependent users. We also test the hypothesis that calling it "diamorphine" instead of "heroin" increases support for this approach.

METHODS

The RAND American Life Panel is a nationally representative, probability-based survey of US adults. Of the 3345 panel members invited to take the survey, 2530 (75.6%) provided a valid response to our question module. Respondents were randomly assigned to have the question refer to the prescribed drug as either "heroin" or "diamorphine." The groups did not significantly differ on sex, age, race/ethnicity, or education. We compare the distribution of responses for the two groups and conduct Pearson's chi-squared test with the Rao-Scott correction.

RESULTS

For those asked whether the US should try prescribing pharmaceutical-grade "heroin," the share answering "Yes" (20.8%) was 15 percentage points lower than those responding "No" (35.8%). When the question asked about "diamorphine," the results were nearly reversed: the share answering "Yes" (30.6%) was almost 12 percentage points higher than those responding "No" (18.9%). The distributions of responses were significantly different (p < 0.001).

CONCLUSIONS

Support for prescribing diamorphine to dependent users is low in the US. While the results are consistent with the hypothesis that referring to heroin as diamorphine may reduce stigma associated with the substance and increase support for prescribing it, opinions may change as individuals learn they are different names for the same substance.

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."

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

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 7 July 2014 to 30 September 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) A total of 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 comprising 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) = 0.011-0.013] and CBD (coefficient = 0.017; CI = 0.015-0.019). 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.

Considering marijuana legalization carefully: insights for other jurisdictions from analysis for Vermont

BACKGROUND AND AIMS

In 2014 the legislature of Vermont, USA passed a law requiring the Secretary of Administration to report on the consequences of legalizing marijuana. The RAND Corporation was commissioned to write that report. This paper summarizes insights from that analysis that are germane to other jurisdictions.

METHOD

Translation of key findings from the RAND Corporation report to the broader policy debate.

RESULTS

Marijuana legalization encompasses a wide range of possible regimes, distinguished along at least four dimensions: which organizations are allowed to produce and supply the drug, the regulations under which they operate, the nature of the products that can be distributed and taxes and prices. Vermont's decriminalization had already cut its costs of enforcing marijuana prohibition against adults to about $1 per resident per year. That is probably less than the cost of regulating a legal market. Revenues from taxing residents' purchases after legalization could be many times that amount, so the main fiscal cost of prohibition after decriminalization relative to outright legalization may be foregone tax revenues, not enforcement costs. Approximately 40 times as many users live within 200 miles of Vermont's borders as live within the state; drug tourism and associated tax revenues will be important considerations, as will be the response of other states. Indeed, if another state legalized with lower taxes, that could undermine the ability to collect taxes on even Vermont residents' purchases.

CONCLUSIONS

Analysis of possible outcomes if Vermont, USA, legalized marijuana reveal that choices about how, and not just whether, to legalize a drug can have profound consequences for the effects on health and social wellbeing, and the choices of one jurisdiction can affect the options and incentives available to other jurisdictions.

Evolution of the United States Marijuana Market in the Decade of Liberalization Before Full Legalization

The past decade has seen a remarkable liberalization of marijuana policies in many parts of the United States. We analyze data from the National Survey on Drug Use and Health (NSDUH) for coinciding changes in the marijuana market from 2002 to 2013, including market size, number and demographics of customers, and varying means of acquiring the drug. Results suggests that (a) the national market has grown, especially in terms of the number of daily users; (b) marijuana users remained economically “downscale” over this period, and in many ways resemble cigarette users; (c) distribution networks appear to be professionalizing in a sense, as fewer users obtain marijuana socially; (d) the typical purchase has gotten smaller by weight but not price paid, suggestive of a trend toward higher potencies; (e) marijuana expenditures vary by user group; and (f) respondents with medical marijuana recommendations differ from other users in systematic ways.

Marijuana Markets: Inferences from Reports by the Household Population

Generally more is known about drug use and demand than about markets and supply, in large part because population survey data are available while market data are not. Although the household population represents a relatively small proportion of users of hard drugs, it represents a large proportion of the population using marijuana and participating in marijuana markets. This paper provides a description of marijuana market and acquisition patterns as reported by participants in the 2001 National Household Survey on Drug Abuse. We find that most respondents obtain marijuana indoors (87%), from a friend or relative (89%), and for free (58%). Retail marijuana distribution appears to be embedded in social networks rather than being dominated by “professional” sellers. Despite these contrasts with stereotypical street markets for cocaine and heroin, there are also similarities, such as evidence of quantity discounts and a minority of users accounting for the majority of purchases. We estimate that there are on the order of 400 million retail marijuana purchases in the U.S. each year and that the average purchase size is small, about six or seven joints.

Limited Rationality and the Limits of Supply Reduction

Drug markets have been targeted for increasingly tough enforcement, yet retail prices for cocaine and heroin have fallen by 70–80%. No research has explained adequately why prices have fallen. This paper explores the possibility that part of the explanation may lie in the failure of drug dealers to respond to risks the way the simplest rational actor models might predict.

How Many People Does the U.S. Imprison for Drug Use, and Who are They?

Data from the Survey of Inmates in Federal and State Correctional Facilities, 1997 are used to estimate the number of drug-law violators in U.S. prisons solely because of their drug use and not because of involvement in drug distribution or other offenses. The estimates (5,380 to 41,047) are much lower than would be implied by naively assuming that conviction for drug possession implies no involvement in drug distribution. Implied imprisonment risk per year of use is also low, perhaps an hour per year of use for marijuana, in part because expected time served is half that for those clearly involved in drug distribution.

Cocaine's fall and marijuana's rise: questions and insights based on new estimates of consumption and expenditures in US drug markets

AIMS

Drug policy strategies and discussions often use prevalence of drug use as a primary performance indicator. However, three other indicators are at least as relevant: the number of heavy users, total expenditures and total amount consumed. This paper stems from our efforts to develop annual estimates of these three measures for cocaine (including crack), heroin, marijuana and methamphetamine in the United States.

METHODS

The estimates exploit complementary strengths of a general population survey (National Survey on Drug Use and Health) and both survey and urinalysis test result data for arrestees (Arrestee Drug Abuse Monitoring Program), supplemented by many other data sources.

RESULTS

Throughout the 2000s US drug users spent in the order of $100 billion annually on these drugs, although the spending distribution and use patterns changed dramatically. From 2006 to 2010, the amount of marijuana consumed in the United States probably increased by more than 30%, while the amount of cocaine consumed in the United States fell by approximately 50%. These figures are consistent with supply-side indicators, such as seizures and production estimates. For all the drugs, total consumption and expenditures are driven by the minority of users who consume on 21 or more days each month.

CONCLUSIONS

Even for established drugs, consumption can change rapidly. The halving of the cocaine market in five years and the parallel (but independent) large rise in daily/near-daily marijuana use are major events that were not anticipated by the expert community and raise important theoretical, research, and policy issues.

How much of the cocaine market are we missing? Insights from respondent-driven sampling in a mid-sized American city

BACKGROUND

Studying markets for illegal drugs is important, but difficult. Data usually come from a selected subset of consumers, such as arrestees, treatment clients, or household survey respondents. There are rarely opportunities to study how such groups may differ from other market participants or how much of total consumption they represent.

METHODS

This paper uses respondent-driven sampling (RDS) of drug users in a mid-sized American city to estimate the shares of cocaine (powder and crack) users and expenditures that are attributable to different combinations of these groups.

RESULTS

We find that those arrested in the last year accounted for 34% of past-month cocaine users and 40% of past-week cocaine spending in the RDS sample. Augmenting past-year arrestees with those who received treatment in the past year increases these values to 44% (users) and 55% (spending).

CONCLUSIONS

Our results suggest that estimates based only on people who were arrested and/or treated in the past year would have to be inflated by 100-200% to capture the market totals. Adding those who own or rent their place of residence increased coverage in this study to 76% (users) and 81% (spending), suggesting that in theory the inflation factor could be reduced to 23-32% by supplementing data on arrestees and treatment populations with household data, although in practice rates of under-reporting by survey respondents may make coverage (sampling frame) a secondary concern for household surveys.

High-frequency drug purity and price series as tools for explaining drug trends and harms in Victoria, Australia

AIMS

Methamphetamine-related harms in Victoria have increased recently in the context of stable or declining use prevalence. We determine how changes in price and purity of methamphetamine compared to other drugs such as heroin may, in part, explain these divergent patterns.

METHODS

Detailed methamphetamine and heroin purchase price data from 2152 participant interviews from the Melbourne Injecting Drug User cohort study were used to generate drug price series for the period January 2009-June 2013. Data on drug purity from 8818 seizures made within Victoria were used to generate drug purity series during the same period. Purity-adjusted price data for methamphetamine and heroin were obtained for the period 2009-13 by combining the two data sets.

RESULTS

While the average purity of heroin seizures remained consistent and low, the average purity of powder and of crystal methamphetamine seizures increased from 12% [95% confidence interval (CI) = 10-14%] to 37% (95% CI = 20-54%) and 21% (95% CI = 18-23%) to 64% (95% CI = 60-68%), respectively. Crystal methamphetamine purity was bimodal, with observations generally less than 20% or greater than 70%. The average unadjusted price per gram for heroin decreased from $374 (95% CI = $367-381) to $294 (95% CI = $280-308), powder methamphetamine did not change significantly from $252 (95% CI = $233-271), and crystal methamphetamine increased substantially from $464 (95% CI = $416-511) in 2009 to $795 (95% CI = $737-853) in 2011. This increase was offset by an even greater increase in purity, meaning the average purity-adjusted price per gram declined. Furthermore, pure prices of both methamphetamine forms were similar, whereas their unadjusted prices were not. The pure price of heroin fluctuated with no ongoing trends.

CONCLUSIONS

Decreases in methamphetamine purity-adjusted price along with the bimodality of crystal methamphetamine purity may account for some of the recent increase in methamphetamine-related harm. For a given amount spent, methamphetamine purchase power has increased and the presence of extreme purity variations may challenge individuals' control of consumption.