Effects Of Medical Marijuana Laws Research Articles

The Public Health Effects of Legalizing Marijuana

Thirty-six states have legalized medical marijuana and 18 states have legalized the use of marijuana for recreational purposes. In this paper, we review the literature on the public health consequences of legalizing marijuana, focusing on studies that have appeared in economics journals as well as leading public policy, public health, and medical journals. Among the outcomes considered are: youth marijuana use, alcohol consumption, the abuse of prescription opioids, traffic fatalities, and crime. For some of these outcomes, there is a near consensus in the literature regarding the effects of medical marijuana laws (MMLs). As an example, leveraging geographic and temporal variation in MMLs, researchers have produced little credible evidence to suggest that legalization promotes marijuana use among teenagers. Likewise, there is convincing evidence that young adults consume less alcohol when medical marijuana is legalized. For other public health outcomes such as mortality involving prescription opioids, the effect of legalizing medical marijuana has proven more difficult to gauge and, as a consequence, we are less comfortable drawing firm conclusions. Finally, it is not yet clear how legalizing marijuana for recreational purposes will affect these and other important public health outcomes. We will be able to draw stronger conclusions when more posttreatment data are collected in states that have recently legalized recreational marijuana. (JEL I12, I18, K32, K42, R41)

Long-Term Impact of Medical Marijuana Laws on the Burden of Cannabis Use Disorders in US Male and Female Adolescents and Young Adults.

Deregulation of cannabis use has raised concerns regarding its potential effects on health, particularly in adolescents and young adults. Here, we extracted data from the Global Burden of Disease database to estimate the long-term effect (> 5 years) of medical marijuana laws (MML) on 2019 cannabis use disorders Disability Adjusted Life Years (2019 CUD DALYs) in US male and female adolescents (15-19 years old) and young adults (20-24 years old). Socio-cultural, demographic and economic characteristics were used as baseline covariates. To improve the robustness of estimation, we took advantage of machine learning techniques. We found no significant effect of MML on 2019 CUD DALYS in each of our four age/sex groups. Estimates from a marginal structural model taking into account age and sex strata in the same model were also non-significant. Our findings suggest that MML may have a negligible effect (if any) on cannabis use disorders in this population group.

The effects of medical marijuana laws on birth outcomes: Evidence from early adopting U.S. states

This paper examines the effects of state-level medical marijuana laws (MMLs) in the U.S. on birth outcomes, including birth weight, length of gestation, and Apgar scores. Using individual-level natality data from the National Center for Health Statistics from 1990 to 2013, we take advantage of the geographic and temporal variation in the implementation of MMLs in a difference-in-differences estimation framework with state and year fixed effects and state-specific time trends. Overall, we find that MMLs have no impact on gestation period or Apgar scores. While MMLs lead to a statistically significant increase in birth weight by 4.4 g (0.13%), this effect is practically small. Furthermore, we find little variation in the effects of MMLs on birth outcomes across different socioeconomic subgroups and observe no lagged negative effects of MMLs on birth outcomes of children born in the MML states in the years following the legalization of medical marijuana.

Marijuana and alcohol: Evidence using border analysis and retail sales data

AbstractWe use retail scanner data on purchases of alcoholic beverages across US counties for 2006 to 2015 to study the link between medical marijuana laws (MMLs) and alcohol consumption. To do this, we exploit differences in the timing of marijuana laws among states and find that they are substitutes. We show that unlike traditional national‐level analysis, focusing on contiguous‐border county pairs provides unbiased estimates of the effect of MMLs on alcohol sales. Specifically, alcohol sales in counties located in MML states decreased by 12.4%. Results are robust to including placebo effective dates for MMLs in treated states.

Medical Marijuana Laws and Labor Market Outcomes: Estimates Using a Border Discontinuity Design

This study provides the first county-level analysis on the employment and wage effects of medical marijuana laws (MMLs). Since traditional state-level difference-in-differences analyses might not fully capture unobserved heterogeneity in changes in the local labor markets, we employ a border discontinuity design to improve the comparability between the treated and control groups. Specifically, we compare changes in employment and wages between contiguous border counties of neighboring states with and without MMLs. Using county-quarter level data from the 1990-2012 Quarterly Census of Employment and Wages, we find that MMLs are associated with a 1.5 percent decline in wages. We also find that the wage effect occurs with a two-year lag and appears to be more pronounced in the trade, transportation, and utilities sectors. However, the estimates of the effect of MMLs on employment counts are imprecise. Finally, our additional analysis provides suggestive evidence that MMLs are associated with a modest increase in labor market slack, which could potentially explain the wage decline in the absence of employment adjustment.

The effect of cannabis laws on opioid use

BackgroundMany Americans rely on opioids at varying dosages to help ameliorate their suffering. However, empirical evidence is mounting that opioids are ineffective at controlling non-cancer related chronic pain, and many argue the strategies meant to relieve patient suffering are contributing to the growing opioid epidemic. Concurrently, several states now allow the use of medical cannabis to treat a variety of medical conditions, including chronic pain. Needing more exploration is the impact of cannabis laws on general opioid reliance and whether chronic pain sufferers are opting to use cannabis medicinally instead of opioids. MethodsThis study investigates the effect of Medical Marijuana Laws (MML)s on opioid use and misuse controlling for a number of relevant factors using data from several years of the National Survey on Drug Use and Health and multivariate logistic regression and longitudinal analysis strategies. ResultsResults provide evidence that MMLs may be effective at reducing opioid reliance as survey respondents living in states with medical cannabis legislation are much less apt to report using opioid analgesics than people living in states without such laws, net other factors. Results further indicate that the presence of medicinal cannabis legislation appears to have no influence over opioid misuse. ConclusionMMLs may ultimately serve to attenuate the consequences of opioid overreliance.

THE EFFECTS OF RECREATIONAL MARIJUANA LEGALIZATION AND DISPENSING ON OPIOID MORTALITY

This study documents how the changing legal status of marijuana has impacted mortality in the United States over the past two decades. We use a difference‐in‐difference approach to estimate the effect of medical marijuana laws (MML) and recreational marijuana laws (RML) on fatalities from opioid overdoses, and we find that marijuana access induces sharp reductions in opioid mortality rates. Our research corroborates prior findings on MMLs and offers the first causal estimates of RML impacts on opioid mortality to date, the latter of which is particularly important given that RMLs are far more expansive in scope and reach than MMLs. In our preferred econometric specification, we estimate that RMLs reduce annual opioid mortality in the range of 20%–35%, with particularly pronounced effects for synthetic opioids. In further analysis, we demonstrate how RML impacts vary among demographic groups, shedding light on the distributional consequences of these laws. Our findings are especially important and timely given the scale of the opioid crisis in the United States and simultaneously evolving attitudes and regulations on marijuana use. (JEL I18, K32, H75)

A quasi-experimental evaluation of marijuana policies and youth marijuana use

ABSTRACTBackground: Marijuana use carries risks for adolescents’ well-being, making it essential to evaluate effects of recent marijuana policies.Objectives: This study sought to delineate associations between state-level shifts in decriminalization and medical marijuana laws (MML) and adolescent marijuana use.Methods: Using data on 861,082 adolescents (14 to 18+ years; 51% female) drawn from 1999 to 2015 state Youth Risk Behavior Surveys (YRBS), difference-in-differences models assessed how decriminalization and MML policy enactment were associated with adolescent marijuana use, controlling for tobacco and alcohol policy shifts, adolescent characteristics, and state and year trends.Results: MML enactment was associated with small significant reductions (OR = 0.911, 95% CI [0.850, 0.975]) of 1.1 percentage points in current marijuana use, with larger significant declines for male, Black, and Hispanic (2.7–3.9 percentage points) adolescents. Effects of MML increased significantly with each year of exposure (OR = 0.980, 95% CI [0.968, 0.992]). In contrast, decriminalization was not associated with significant shifts in use for the sample as a whole, but predicted significant declines in marijuana use among 14-year olds and those of Hispanic and other ancestry (1.7–4.4 percentage points), and significant increases among white adolescents (1.6 percentage points). Neither policy was significantly associated with heavy marijuana use or the frequency of use, suggesting that heavy users may be impervious to such policy signals.Conclusion: As the first study to concurrently assess unique effects of multiple marijuana policies, results assuage concerns over potential detrimental effects of more liberal marijuana policies on youth use.

The Effect of Medical Marijuana Laws on the Health and Labor Supply of Older Adults: Evidence from the Health and Retirement Study

Older adults are at elevated risk of reducing labor supply due to poor health, partly because of high rates of symptoms that may be alleviated by medical marijuana. Yet, surprisingly little is known about how this group responds to medical marijuana laws (MMLs). We quantify the effects of state medical marijuana laws on the health and labor supply of adults age 51 and older, focusing on the 55 percent with one or more medical conditions with symptoms that may respond to medical marijuana. We use longitudinal data from the Health and Retirement Study to estimate event study and differences-in-differences regression models. Three principle findings emerge from our analysis. First, active state medical marijuana laws lead to lower pain and better self-assessed health among older adults. Second, state medical marijuana laws lead to increases in older adult labor supply, with effects concentrated on the intensive margin. Third, the effects of MMLs are largest among older adults with a health condition that would qualify for legal medical marijuana use under current state laws. Findings highlight the role of health policy in supporting work among older adults and the importance of including older adults in assessments of state medical marijuana laws.

High times: The effect of medical marijuana laws on student time use

Medical marijuana laws (MMLs) represent a major change of marijuana policy in the U.S. Previous research shows that these laws increase marijuana use among adults. In this paper, we estimate the effects of MMLs on secondary and post-secondary students’ time use using data from the American Time Use Survey. We apply a difference-in-differences research design and estimate flexible fixed effects models that condition on state fixed effects and state-specific time trends. We find no effect of MMLs on secondary students’ time use. However, we find that college students in MML states spend approximately 20% less time on education-related activities and 20% more time on leisure activities than their counterparts in non-MML states. These behavioral responses largely occur during weekends and summer when students have more spare time. Finally, the impacts of MMLs are heterogeneous and stronger among part-time college students, who are more likely to be first-generation college goers and to come from underrepresented racial and ethnic groups.

Joint culpability: The effects of medical marijuana laws on crime

Most U.S. states have passed medical marijuana laws. In this paper, we study the effects of these laws on violent and property crime. We first estimate models that control for city fixed effects and flexible city-specific time trends. To supplement this regression analysis, we use the synthetic control method which can relax the parallel trend assumption and better account for heterogeneous policy effects. Both the regression analysis and the synthetic control method suggest no causal effects of medical marijuana laws on violent or property crime at the national level. We also find no strong effects within individual states, except for in California where the medical marijuana law reduced both violent and property crime by 20%.

The effects of medical marijuana laws on cannabis-involved driving

This study uses data from the Fatality Analysis Reporting System and a differences-in-differences model to examine the effect of state medical marijuana laws (MMLs) on cannabis-involved driving among U.S. drivers involved in a fatal crash between 1993–2014. Findings indicate that MMLs in general have a null effect on cannabis-positive driving, as do state laws with specific supply provisions including home cultivation and unlicensed or quasi-legal dispensaries. Only in jurisdictions with state-licensed medical marijuana dispensaries did the odds of marijuana-involved driving increase significantly by 14 percent, translating into an additional 87 to 113 drivers testing positive for marijuana per year. Sensitivity analyses reveal these findings to be generally robust to alternate specifications, although an observed spillover effect consistent with elevated drugged driving enforcement in bordering states weakens a causal interpretation. Still, reasonable policy implications are drawn regarding drugged driving prevention/enforcement and regulations governing dispensary delivery services and business siting decisions.

The Effect of Medical Marijuana Laws on Marijuana-Related Attitude and Perception Among US Adolescents and Young Adults.

Marijuana liberalization policies are gaining momentum in the USA, coupled with limited federal interference and growing dispensary industry. This evolving regulatory landscape underscores the importance of understanding the attitudinal/perceptual pathways from marijuana policy to marijuana use behavior, especially for adolescents and young adults. Our study uses the restricted-access National Survey on Drug Use and Health (NSDUH) 2004-2012 data and a difference-in-differences design to compare the pre-policy, post-policy changes in marijuana-related attitude/perception between adolescents and young adults from ten states that implemented medical marijuana laws during the study period and those from the remaining states. We examined four attitudinal/perception pathways that may play a role in adolescent and young adult marijuana use behavior, including (1) perceived availability of marijuana, (2) perceived acceptance of marijuana use, (3) perceived wrongfulness of recreational marijuana use, and (4) perceived harmfulness of marijuana use. We found that state implementation of medical marijuana laws between 2004 and 2012 was associated with a 4.72% point increase (95% CI 0.15, 9.28) in the probability that young adults perceived no/low health risk related to marijuana use. Medical marijuana law implementation is also associated with a 0.37% point decrease (95% CI - 0.72, - 0.03) in the probability that adolescents perceived parental acceptance of marijuana use. As more states permit medical marijuana use, marijuana-related attitude/perception need to be closely monitored, especially perceived harmfulness. The physical and psychological effects of marijuana use should be carefully investigated and clearly conveyed to the public.

Medical marijuana laws and adolescent marijuana use in the United States: a systematic review and meta-analysis.

AimsTo conduct a systematic review and meta‐analysis of studies in order to estimate the effect of US medical marijuana laws (MMLs) on past‐month marijuana use prevalence among adolescents.MethodsA total of 2999 papers from 17 literature sources were screened systematically. Eleven studies, developed from four ongoing large national surveys, were meta‐analyzed. Estimates of MML effects on any past‐month marijuana use prevalence from included studies were obtained from comparisons of pre–post MML changes in MML states to changes in non‐MML states over comparable time‐periods. These estimates were standardized and entered into a meta‐analysis model with fixed‐effects for each study. Heterogeneity among the study estimates by national data survey was tested with an omnibus F‐test. Estimates of effects on additional marijuana outcomes, of MML provisions (e.g. dispensaries) and among demographic subgroups were abstracted and summarized. Key methodological and modeling characteristics were also described. Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines were followed.ResultsNone of the 11 studies found significant estimates of pre–post MML changes compared with contemporaneous changes in non‐MML states for marijuana use prevalence among adolescents. The meta‐analysis yielded a non‐significant pooled estimate (standardized mean difference) of −0.003 (95% confidence interval = −0.012, +0.007). Four studies compared MML with non‐MML states on pre‐MML differences and all found higher rates of past‐month marijuana use in MML states pre‐MML passage. Additional tests of specific MML provisions, of MML effects on additional marijuana outcomes and among subgroups generally yielded non‐significant results, although limited heterogeneity may warrant further study.ConclusionsSynthesis of the current evidence does not support the hypothesis that US medical marijuana laws (MMLs) until 2014 have led to increases in adolescent marijuana use prevalence. Limited heterogeneity exists among estimates of effects of MMLs on other patterns of marijuana use, of effects within particular population subgroups and of effects of specific MML provisions.

RETRACTED: Investigating the effects of medical marijuana laws on educational attainment

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).This article has been retracted at the request of the authors. The main set of results appeared earlier in a paper by Plunk et al (2016), that should have been cited. Both papers use similar methods and reach the same conclusions using different data:“The impact of adolescent exposure to medical marijuana laws on high school completion, college enrollment and college degree completion” by Andrew D. Plunk, Arpana Agrawal, Paul T. Harrell, William F. Tate, Kelli England Will, Jennifer M. Mellor and Richard A. Grucza. Drug and Alcohol Dependence 168 (2016) 320–327. https://dx.doi.org/10.1016/j.drugalcdep.2016.09.002

Is Legal Pot Crippling Mexican Drug Trafficking Organisations? The Effect of Medical Marijuana Laws on US Crime

We show that the introduction of medical marijuana laws (MMLs) leads to a decrease in violent crime in states that border Mexico. The reduction in crime is strongest for counties close to the border (less than 350km), and for crimes that relate to drug trafficking. In addition, we find that MMLs in inland states lead to a reduction in crime in the nearest border state. Our results are consistent with the theory that decriminalization of the production and distribution of marijuana leads to a reduction in violent crime in markets that are traditionally controlled by Mexican drug trafficking organisations. This article is protected by copyright. All rights reserved.

Helping Settle the Marijuana and Alcohol Debate: Evidence from Scanner Data

We use retail scanner data on purchases of alcoholic beverages across US counties for 2006-2015 to study the link between medical marijuana laws (MMLs) and alcohol consumption. To do this we first exploit differences in the timing of marijuana laws among states and find that they are substitutes. We show that unlike traditional national-level analysis, focusing on contiguous border county-pairs provides unbiased estimates of the effect of MMLs on alcohol sales. Specifically, counties located in MML states reduced monthly alcohol sales by 12.4 percent. Results are robust to including placebo effective dates for MMLs in treated states.

The Effects of Medical Marijuana Laws on Prescribed Opioids and Other Prescription Drugs

More than half of the US population lives in a state that has adopted medical marijuana laws (MMLs). Studies show that most medical marijuana patients use marijuana for managing their pain with the overwhelming majority of them preferring it to opioids. Despite ongoing pro-marijuana policies and the growing trend of public acceptance, the evidence on how people change their prescription use due to the availability of marijuana as an alternative treatment is limited. Using the variations across state MMLs between 1996 and 2014 of Medical Expenditure Panel Survey (MEPS) this paper estimates the effects of MMLs on prescription drug utilization, with a focus on opioids. I find that MMLs lead to a $2.47 decrease in per person prescribed opioid spending among young adults (ages 18-39) over a year. Most of this decrease results from the intensive margin of use and MML states that allow home cultivation experience even larger decreases. Furthermore, the decreasing effects are persistent over time and they get stronger following the years of implementation. MMLs also decrease the number of opioid pill use among young adults. I do not find any discernible impact on older populations' opioid utilization. I then investigate the effects on other prescriptions for which marijuana can be a potential substitute and find the allowance of dispensaries is generally associated with decreases, although the effects depend on the the type of MML, the margin of use and age.

Commentary on Burdzovic Andreas & Bretteville-Jensen (2017): Cannabis use opportunities-an under-researched factor in substance use epidemiology.

Assessment of realistic cannabis use opportunities increases understanding of population-level changes in cannabis use behaviors among adolescents. In an era of rapidly changing cannabis policy, more nuanced models of cannabis use, exploring the pathway from first use opportunity to incident cannabis use, can inform the development of public health strategies. A large body of research has aimed to learn about the causal relationships that affect adolescent cannabis use decisions. During the last decade, much of this research has focused upon what effect, if any, the rapidly changing medical marijuana laws (MML) or recreational marijuana laws (RML) have on adolescent cannabis use. Within this body of literature, the standard model is investigated without reference to whether a person had a realistic cannabis use opportunity. This yields a simple model that combines two potential mechanisms of action, namely that MMLs and RMLs might increase adolescent access to cannabis or might increase willingness to use among those with opportunity. By explicating a model that differentiates realistic cannabis use opportunities from willingness to use the drug, given such opportunities, future analysis on the post-implementation effects of MMLs and RMLs can begin to explain a causal mechanism linking MMLs and RMLs to changes in cannabis use. In this issue of Addiction, Burdzovic Andreas et al. aimed to investigate the role of cannabis use opportunities in understanding adolescent cannabis use in a nationally representative sample of Norwegian adolescents 1. In this study, a realistic cannabis use opportunity was defined by a participant endorsing either (1) ever using cannabis in their life-time or (2) ever having the possibly to try cannabis without actually doing so. While such an investigation of cannabis use opportunities is not unique to this study by Burdzovic Andreas et al., the vast majority of extant studies have used some iteration of three similar questions about cannabis use opportunities: (1) has anyone approached you to sell you cannabis? 2; (2) have you ever had a chance to try cannabis if you had wanted to? 3-7; or (3) has someone either offered you cannabis or cannabis was present when others were consuming and you could have done so? 8. To the best of my knowledge, only a single study 5 has taken the question about cannabis use opportunities a step further and asked participants: ‘Who provided you with the opportunity to use (drug) for the first time?’, providing participants options that included: (a) I never had the opportunity; (b) I sought it myself; (c) a parent; (d) a sibling; (e) other family member; (f) a friend; or (g) another person. Such details about use opportunities are needed to inform interventions that can target the primary mechanisms giving rise to cannabis use among adolescents. Different types of use opportunities will necessitate different interventions. Use opportunities can vary substantially across several factors, including who is offering the drug (e.g. a close friend or family member or someone who is unknown to the person), how actively the drug is sought out (e.g. the person might seek out the drug or the person might receive an unsolicited offer to use the drug), how the drug is procured (e.g. it might be stolen from a family member's supply or directly offered for sale), the cost of the drug (e.g. free, $5, $20) and the drug's form (e.g. edible, inhalable smoke, inhalable vapor). Each mechanism will suggest a different intervention to target that specific mechanism of use opportunity. If, for example, adolescents who live in US states that allow the use of medicinal marijuana tend to report stealing cannabis from a family member's supply, an intervention might focus upon increasing the use of lockboxes or other physical barriers that can be used to secure medical marijuana in the house, whereas targeted information campaigns might be the primary mode of intervention to reduce an adolescent's willingness to use cannabis that is offered by a friend. When the type of use opportunities vary across different locations, the mechanisms that give rise to adolescent cannabis use opportunities will need to be elucidated fully to inform targeted interventions most accurately. In particular, specific questions about cannabis use opportunities are needed to clarify the mechanisms that have been hypothesized previously to link MMLs and RMLs to population changes in cannabis use (i.e. increased access to cannabis, changing cannabis use norms, or both). The study by Burdzovic Andreas et al. into the role of realistic cannabis use opportunities and willingness to use the drug, given such opportunities, highlights the need for a more nuanced model, with more specific questions about cannabis use opportunities, to explain marijuana initiation among adolescents. None. D.S.F. is supported by the National Institute on Drug Abuse (T32DA031099).

Medical Marijuana Laws May Be Associated With A Decline In The Number Of Prescriptions For Medicaid Enrollees.

In the past twenty years, twenty-eight states and the District of Columbia have passed some form of medical marijuana law. Using quarterly data on all fee-for-service Medicaid prescriptions in the period 2007-14, we tested the association between those laws and the average number of prescriptions filled by Medicaid beneficiaries. We found that the use of prescription drugs in fee-for-service Medicaid was lower in states with medical marijuana laws than in states without such laws in five of the nine broad clinical areas we studied. If all states had had a medical marijuana law in 2014, we estimated that total savings for fee-for-service Medicaid could have been $1.01billion. These results are similar to those in a previous study we conducted, regarding the effects of medical marijuana laws on the number of prescriptions within the Medicare population. Together, the studies suggest that in states with such laws, Medicaid and Medicare beneficiaries will fill fewer prescriptions.