Given that many smoking studies use CO as an endpoint for bio-verifying tobacco use status, researchers will need to determine how to use this information.It is unknown whether excluding marijuana use was done to isolate cigarette smoking as a source of CO for bio-verifying smoking reduction, or whether this exclusion was a strategy to exclude drug use. For example, dependence on chemicals other than nicotine is common exclusion criteria for e-cigarette switching studies. Interventionists should be aware that excluding cigarette smokers who use marijuana use will significantly decrease study generalizability. Researchers who wish to include combustible marijuana users in their study sample are advised to conduct a nuanced measurement of product use and account for combustible marijuana use when bio-verifying tobacco use status.The study includes several important limitations. The study was conducted in two geographical locations in the United States and among two different racial/ethnic groups and findings may not generalize to other populations. Additionally, the product characteristics and frequency patterns of marijuana use came from a relatively small sample that may not generalize to other populations of marijuana users. Findings must also be taken in light of a sample of smokers willing to switch to e-cigarettes and provided e-cigarettes at no cost for 6 weeks.
Self-reported marijuana use was higher at the San Diego site than the Kansas City site. Although participants were told their responses were deidentified and confidential, Kansas City participants could have felt pressure to conceal marijuana use due to the state’s medicinal-only status, compared with the San Diego site where recreational marijuana use is legal. In addition to decreased comfort of reporting due to associated legal risks,ebb and flow flood table there are also practical considerations that may contribute to less use such as accessibility to purchasing and exposure to advertising. Prevalence of marijuana use has been reported highest in states with legal recreational use.To address reporting bias in a multi-site setting, measuring a biomarker of cannabis use is recommended. It is also possible that the younger age of San Diego study participants compared with Kansas City participants contributed to differential marijuana use, as age is associated with marijuana use.Finally, study outcomes were taken at 6-week post baseline and the long-term impact of marijuana use on cigarette reduction and related health effects is an important topic for future study. While this study captured a majority of combustible marijuana use, understanding if there are reinforcing sensory components of vaping marijuana and vaping nicotine e-liquid remains to be studied.As of 2015, twenty-four U.S. jurisdictions have medical marijuana laws , which provide legal protection for individuals who use marijuana for medical purposes, physicians who recommend marijuana to patients with certain medical conditions, and growers and distributors who supply these patients. Past studies have exploited state-time variation in MML enactment to estimate the effects of liberalization on recreational marijuana use,1 traffic fatalities , obesity , suicides , and crime .
However, interventions may not attain full steady-state effectiveness immediately upon implementation , and estimation based on the timing of MML passage will likely not capture the full effects of these policies as medical marijuana markets evolve. While MML enactment alone may signal a shift in governmental acceptance of the drug, effects on marijuana availability and price will depend on the specific regulations established by MML policy and the duration of exposure to the more liberal regime. Changes in social access, perceived community approval, and spillover effects to illegal use and other public health outcomes may well vary according to the extent to which legal users and suppliers actively participate in the medical marijuana program. If recreational and medical marijuana consumption decisions are made based on similar consumer optimization problems,2 both medical marijuana participation and use in the general population will follow similar patterns. Understanding the factors that drive changes in medical marijuana participation can thus offer insight into the mechanisms by which MMLs generate spillovers to recreational use and other health outcomes. This is the first paper to investigate the determinants and dynamics of medical marijuana participation by legal users using newly collected data on medical marijuana patient registration rates. While some recent research has examined data on registered patients, these studies have either been descriptive , cross-sectional , or limited to one state . By collecting data on registered patient counts from both administrative and non-administrative sources, this paper presents the most comprehensive state-level monthly panel dataset to date on medical marijuana participation to date. Data was obtained from 1999-2014 for the sixteen states3 that required individuals to register as medical marijuana patients in order to receive the legal protections afforded by the MML.
The data show that there have been dramatic changes in medical marijuana participation over the last two decades. Registered patient counts were relatively low until 2009, when they sharply increased. The number of registered patients continued to climb until mid-2011, when they leveled before resuming an upward trend a few years later. These trend breaks in medical marijuana patient registration rates coincide with the timing of federal enforcement policy changes that have been widely ignored by past research. While federal law has strictly prohibited the use and distribution of marijuana since 1937 regardless of state policy, a federal statement of non-enforcement in MML states was released in October 2009 ; in June 2011, another federal statement was issued to clarify that this did not apply to large-scale producers . To understand the factors responsible for driving these changes in medical marijuana take-up, I first outline a conceptual framework whereby individuals apply to register with the medical marijuana program if the expected utility from registering exceeds that of not registering. Costs to patients include transaction costs associated with registration fees and finding a doctor to provide a recommendation, as well as perceived risk from state and federal enforcement. Benefits include access to legitimate sources of marijuana , which will vary depending on the production limits established by the state’s specific MML regulation. The federal memos are predicted to affect medical marijuana participation through changing the perceived risk associated with federal enforcement for both registered patients and state-legal producers. The empirical results confirm the descriptive evidence showing that the federal memos significantly affected medical marijuana take-up. Controlling for state-level demographic and economic variables or time-invariant state characteristics dampens the magnitude of these effects slightly, but they remain large and statistically significant. However,hydroponic drain table the federal memos did not affect all MML states equally. Interacting the federal memo changes with state-specific supply-side regulations shows that the magnitude of their effects was significantly larger in states that imposed relatively lax restrictions on legal producers. These findings imply that medical marijuana participation is primarily driven by the expected benefits associated with access to legal supply. Additional robustness checks support that the extent of medical marijuana participation is highly responsive to supply-side changes in the legal market. This paper builds on recent work recognizing that heterogeneity in the specifics of state MML regulations may generate heterogeneous effects , and it contributes to a broader economic literature showing that the effects of regulatory changes depend largely on the specifics of their design, implementation, and enforcement.Section 1.2 details the history of marijuana regulation in the U.S. and provides background on modern MMLs and changes in federal enforcement policy. Section 1.3 outlines a conceptual framework to suggest the factors determining medical marijuana participation.
Section 1.4 presents the data, empirical framework, and results for the determinants of medical marijuana participation. Finally, section 1.5 places these results in the context of the existing literature on MMLs, and section 1.6 concludes. The first federal regulation of marijuana was introduced with the Marijuana Tax Act of 1937. The Marijuana Tax Act did not criminalize the possession or use of marijuana, as this was a potential violation of the Tenth Amendment’s limitation on federal power, but instead made it illegal to grow or distribute marijuana unless the grower obtained a federal stamp. Since stamps were largely unavailable and there was no application process, the Act effectively served as federal prohibition . Marijuana use remained limited until the mid-1960s, when the baby boom generation reached adolescence. Thicker drug markets associated with this larger youth cohort resulted in a significant increase in illicit drug use among college and high school students . In 1970, Congress responded by passing the Controlled Substances Act , which repealed the Marijuana Tax Act5 but classified marijuana as a Schedule I substance with high potential for abuse and no accepted medical value.6 The CSA criminalized the manufacture, distribution, and possession of marijuana for both recreational and medicinal purposes, and it provided the system of federal penalties and enforcement that remains in place today. Despite federal prohibition, marijuana use continued to rise in the United States. By the early 1970s, eight million people were using marijuana regularly, at least half a million people were consuming it daily, and 421,000 people were arrested for marijuana offenses annually . In 1972, the National Commission on Marijuana and Drug Abuse, which had been created as part of the CSA, released a comprehensive report based on surveys of health experts and law enforcement officials. The report recommended the removal of criminal penalties for marijuana possession and advocated further scientific research on the substance’s potential medicinal value. President Nixon rejected the Commission’s recommendations, but the 1972 report helped trigger a push toward liberalization policies . In 1972, the National Organization for the Reform of Marijuana Laws filed the first petition to reschedule marijuana. In 1975, the federal government established the Individual Patient Investigational New Drug program, which enabled participating physicians to prescribe marijuana to enrolled patients. The federal program was designed to accept patients with serious illnesses and directly provide them with marijuana through the National Institute on Drug Abuse. While the IND ostensibly established a legal channel by which patients could obtain marijuana, the application process was complicated and burdensome, and only six patients were accepted into the program during its first decade of operation . Still, this signaled a movement toward federal acceptance of marijuana’s medicinal value, and many states began to adopt their own legislation allowing the use of cannabis for medical purposes under specified conditions . Figure 1.1 graphs the number of proposed state-level medical marijuana initiatives from 1972-1995. Statutes are classified as therapeutic research programs , rescheduling provisions, or physician prescription laws. While these laws demonstrated increasing state recognition of marijuana’s therapeutic value, they had little practical significance . The federal approval process for state TRPs was complicated and costly. In the few states that obtained the necessary federal permissions, enrollment was highly restrictive and largely dependent on receiving marijuana from the federal government. In theory, physician prescription laws and rescheduling provisions allow physicians to legally prescribe marijuana for medicinal purposes outside of a TRP.7 However, since the federal CSA classification of marijuana as Schedule I supersedes any state CSA, physicians who prescribe marijuana outside of an officially recognized state TRP risk facing federal sanctions. Additionally, even should a patient obtain a physician’s prescription, these statutes did not establish any legitimate supply channel for patients to obtain marijuana. By 1984, the wave of state medical marijuana initiatives had quickly come to an end. This shift occurred in large part due to the spread of the crack-cocaine epidemic and increased federal emphasis on drug policy enforcement, seizures, and interdictions under the Reagan and Bush Administrations . It became increasingly unlikely that NORML’s 1972 petition would result in federal rescheduling of marijuana, and the government’s IND program was suspended in 1991 and discontinued one year later. State policy mirrored the federal stance, and by 1990 a number of the existing decriminalization and medical cannabis statutes expired or were repealed. The discovery of naturally occurring cannabinoid receptors in the human brain in the early 1990s led to a resurgence of medical interest in the potential therapeutic value of marijuana .8 There was increasing evidence that smoked marijuana offered significant benefits for patients suffering from symptoms of cancer and HIV/AIDS, and in 1995 the Journal of the American Medical Association ran a commentary supporting the use of marijuana for medicinal purposes and calling for increased research. In 1996, with the passage of Proposition 215, California became the first state to establish an effective medical marijuana law that removed criminal penalties for the use, possession, and cultivation of medical marijuana by qualifying patients and their primary caregivers.