Local contexts took on a greater meaning with the transition to a retail model for marijuana access

Consequently, since medical marijuana was legalized in California in 1996 a patchwork of local legislation has developed where regulations governing marijuana differ from one local jurisdiction to the next. These local regulations include hundreds of medical marijuana dispensary bans enacted by cities in California, some of which have been in place for over a decade . As one of the most commonly consumed drugs in the world , marijuana has increasingly become a target of substance abuse prevention efforts as social and political change has resulted in its increased availability and potency . A chief concern among public health professionals and policy makers is that the increased social acceptance and normalization of marijuana use, combined with its expansion into retail settings in states like California will improve ease of access and result in increased usage among youth . This concern has some validity on a national level, where population-based surveys of substance use among adolescents in the U.S. such as the National Survey of Drug Use and Health , the Youth Risk Behavior Survey System , and the Monitoring the Future study have documented increases in the last several years related to lifetime and recent marijuana use in the United States among older teens ,pots for cannabis plants even as their use of illegal drugs, cigarettes, and alcohol declined . Other research findings suggest that the relationship between greater legal access to marijuana and changing social norms regarding adolescents’ perceptions of risk and use of marijuana may not be so straightforward .

Adolescent cannabis use has not been found to differentially increase after states pass medical cannabis laws and the national-level increases in marijuana use documented among older teens have been offset by non-statistically-significant declines in marijuana use among younger teens. This has resulted in relatively stable rates in adolescents’ marijuana use overall . Furthermore, although drastic decreases in the perceived risks related to marijuana use have been observed in the last decade among U.S. adolescents, they have not been followed by a proportional rise in marijuana use in the past decade as they were in previous decades . The changing relationship between adolescents’ perception of the risk of marijuana use and their patterns of use underscores the need for updated empirical research on how the increasing acceptance and accessibility of marijuana use influences adolescent marijuana use behavior in the current legal and cultural context and on a more local level. The relationship between marijuana policy and teen marijuana use in California has been similarly dynamic and complex. California was the first state to legalize medical marijuana use in 1996. This ground-breaking policy and cultural change was associated with lower perceptions of the harm of marijuana use among adolescents and young adults . However, statewide legalization of medical marijuana use for people over the age of 18 who had a recommendation from a licensed physician did not result in a dramatic increase in marijuana use among teens in California . In November of 2003, California approved Senate Bill 420 , which allowed medical marijuana collectives, which had formerly been defined as person-to-person networks of one marijuana supplier to a maximum of five patients, to distribute medical marijuana in a retail setting to an unlimited number of qualified patients.

Qualified patients were defined as any California resident with a recommendation from a licensed physician to use marijuana to treat a health condition. SB 420 also developed a system that issued medical marijuana patients identification cards that certified them as medical marijuana patients with a valid recommendation from a physician. This allowed medical marijuana collectives that formerly existed primarily to link marijuana suppliers to customers via personal networks to evolve into brick and mortar businesses like any other. Enactment of SB 420 in January of 2004 represented the first time that marijuana could be legally be obtained from a retail establishment since it had become a legal product in 1996. Research has shown that state marijuana laws allowing storefront sales for medical marijuana have a greater association with adult marijuana use rates than laws that permit fewer public forms of access, such as home cultivation . Data from the California Heathy Kids Survey 2013 indicate that marijuana use rates among California high school students increased every year for eight years following 2005, the year SB 420 was enacted . Data from the National Survey of Drug Use and Health similarly demonstrated a sustained increase among adolescents aged 12-17 years old following the combined 2005-2006 survey years . These reports do not show a permanent increase in teen marijuana use in California after storefront medical marijuana dispensaries became a reality but their associations with increased marijuana use in the shorter term do make a persuasive case for further study of the impact retail marijuana outlets have on adolescent marijuana use. In response to the proliferation of medical marijuana dispensaries throughout the state, California cities began to exercise their right to “local control” and enacted ordinances to either ban dispensaries from operating within their borders or to allow them to operate under additional restrictions than were required under California law.

Currently over 65% of the cities in California have dispensary bans in place , as do 75 out of the 88 cities in LA County . State-level studies and reports do not capture these local variations in access to marijuana outlets, making it difficult to determine how these controls influence local variations in adolescent marijuana use. For example, the impacts of dispensary operations within neighborhoods have been studied for associations with crime and adult marijuana use ,cannabis flood table but the localized impact of these outlets on the likelihood of a young person using marijuana is unknown. Several factors make Los Angeles County an ideal location to study the effect of dispensaries on adolescent marijuana use. The County of Los Angeles was home to over 10 million people in 2018 , a population that is larger than 42 U.S. states. It is also large and diverse in area, covering 4,084 square miles that span highly concentrated urban areas as well as suburban and rural zones. One of the oldest medical marijuana dispensaries in California, the Los Angeles Cannabis Resource Center, was founded here in 1996 , the same year that medical marijuana use was legalized. Among the 88 incorporated cities in LA County, ten now allow medical marijuana dispensaries . In the Fall of 2016, when the data for this study were collected, there were only six cities in Los Angeles that allowed marijuana dispensaries. However, since one of those cities was the City of Los Angeles, with a population of approximately 4 million people 43% of LA County residents already lived in a city that allowed storefront dispensaries.My experience as a resident of the City of Los Angeles for most of the study period provided the original motivation for this study. Between 2009 and 2015, I saw dispensaries open and close in my Northeast Los Angeles neighborhood with bewildering frequency, including one located directly across the street from an elementary school. Between 2014 and 2016, I was also completing a two-year Prevention Fellowship with the Substance Abuse and Mental Health Services Administration where I tracked developments in marijuana policy, developed literature reviews for the LA County Department of Public Health Substance Abuse Prevention and Control Program , and provided research support to a coalition of SAPC prevention providers and community members dedicated to preventing marijuana use among children and adolescents. It was an interesting time to work in marijuana policy, as Colorado had recently become the first US state to legalize “recreational” marijuana use for adults in 2014. Several ballot measures to do the same in California were already in development and State and local officials acknowledged the need to act quickly in preparation for the possibility that one would be approved by voters in next election. The one unifying concern among prevention advocates, California legislators, and even the lobbying group developing the ballot measure that later became the Adult Use Marijuana Act was to limit the impacts of policies increasing access for adults on youth populations. As this was an issue that was important to me as well, I proposed tracking changes in city ordinances regulating marijuana use in 2014 as a project for my SAMHSA Prevention Fellowship and continued updating the policy database quarterly through the end of 2016. Upon locating a data source with a large enough sample size to compare student behavior at a city level, that policy tracking document became the basis for this dissertation research.

It provided the link between city policies and student marijuana use that could be used to test whether dispensary bans have a dampening effect on adolescent marijuana use. I also believed it was important to include the number of storefront dispensaries in each city in LA County in my analysis. I therefore proposed collecting data on the number and location of the medical marijuana dispensaries in LA County as a research project near the end of my fellowship in September 2016. The basic question motivating this research is whether city regulations banning or restricting storefront dispensaries are effective in reducing youth marijuana use and whether their effects are dependent on any other factors . One hypothesis for why dispensary bans might be effective is that even though they are not always effective in preventing dispensaries from locating in a city, they are likely to result in a lower number of total outlets, which would make access to marijuana less convenient in that city. Alternatively, bans on marijuana storefronts could have a dampening effect on youth marijuana use by signaling that marijuana use is not considered safe or socially acceptable in their community. I also wondered if dispensary bans could prevent marijuana use among high school students by being more effective at reducing the presence of storefront dispensaries near high schools than a city policy that allows dispensaries. This dissertation will test each of these theories.I investigated whether city ordinances restricting dispensaries have a cross-sectional and long-term impact on youth marijuana use. I also explored the mechanisms through which this effect may operate, i.e., whether an impact of dispensary bans on student marijuana is mediated by factors like the number of dispensaries actively operating in a city, students’ perceptions of the risk of marijuana use, or the proximity of dispensaries near their school. To do this I used four linked data sets. One is a database categorizing and compiling the texts of every ordinance that was enacted to regulate marijuana in Los Angeles County municipalities between 2014 and 2016. The database contains the full text of each city ordinance regulating dispensaries, including detailed notes about when they were enacted and amended. Regulations were categorized by whether cities banned or allowed dispensaries, which was the independent variable for all of the analyses presented here. The second data source is a school-based behavioral survey, the California Healthy Kids Survey . The CHKS survey was used for the measures of lifetime and recent marijuana that were the dependent variables for all of these analyses. The CHKS survey has included standardized questions on marijuana use and the perceived risk of marijuana use since it began to be administered statewide in the late 1990’s and is the only survey of adolescent behavior that is conducted on large enough scale to allow for reliable measurement of marijuana use among high school students in LA County at the city level. I used CHKS survey data from the 2005/2006 school year through the 2016/2017 school year for this dissertation. Students’ behavioral data was linked to location using the third dataset, the California Schools Directory. The California Schools Directory is a listing of school addresses that is maintained by the California Department of Education. The LA County public schools that participated in the CHKS survey were linked to their location in cities by the California Department of Education identification code, a unique code for each school that is common to both the CHKS survey and California Schools Directory. The fourth dataset is a collection of the addresses of dispensaries that were active in LA County in September of 2016, which I obtained from online searches of dispensary listing websites like Weedmaps.