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The legalization of recreational marijuana is a pivotal policy change, and its social consequences remain largely unknown. Central to the public concern is its impact on crime, about which competing views exist and empirical studies have yielded mixed results. Based on Uniform (UCR) data from 2007 to 2017, this study used Difference in Differences (DID) analysis to examine the impact of recreational marijuana legalization on the rates of a variety of serious crimes in Oregon, which passed its recreational marijuana law (RML) in late 2014. Results provide some evidence demonstrating a crime-exacerbating effect of recreational marijuana legalization, as reflected by substantial increases in the rates of multiple types of serious crimes as measured by the UCR in Oregon relative to non-legalized states following legalization, including property and violent crime overall, as well as other crimes such as burglary, motor vehicle theft, larceny, and aggravated assault.


The last two decades saw dramatic changes in policies associated with marijuana use: over 30 states in the United States (U.S.) have legalized medical marijuana, and, more remarkably, there is a trend of legalizing recreational marijuana. Colorado and Washington State first legalized marijuana for recreational use in late 2012, and, to date, 11 states and the District of Columbia have also legalized marijuana for recreational purposes, which may include production, possession, and retail sale, although marijuana remains an illegal drug under the federal Controlled Substances Act. Notably, this pivotal policy change appears not to be restricted within the borders of the United States, but has global dimensions, shown by the recent recreational marijuana legalization in Canada and Uruguay.

As a social experiment, marijuana legalization, especially for recreational purposes, has generated concerns about its impact on public safety. Central to this is an ongoing debate on whether legalization increases or decreases crime rates (Lu et al., 2019). Opponents argue that marijuana legalization would increase crime not only because marijuana may be a gateway to more serious drugs such as cocaine and heroin that are closely associated with crime, but also because of the potential criminogenic effects of the increasing presence of marijuana dispensaries (Cleveland & Wiebe, 2008; Kepple & Freisthler, 2012). Proponents assert that legalization would lead to lower crime rates given the decriminalization of this drug and the reduction in the underground marijuana market that tends to generate criminal activities (Trilling, 2016, September 23). Proponents also argue that legalization would have a crime-reducing effect because the police would be able to re-allocate resources and efforts to more serious crimes rather than focusing on marijuana possession arrests, which would in turn lead to increased crime clearance rates and deterrence effects (Makin et al., 2019). Despite these competing views about the impact of recreational marijuana legalization on crime and public safety, empirical studies using rigorous methodologies to examine this issue are few, yielding mixed results. While there is some evidence suggesting recreational marijuana dispensaries are associated with substantial increases in crime rates and disorder at the neighborhood level (Hughes, Schaible, & Jimmerson, 2019), other studies have either demonstrated a crime-reducing effect from marijuana legalization or the operation of marijuana dispensaries (Brinkman & Mok-Lamme, 2019; Dragone, Prarolo, Vanin, & Zanella, 2019; Wu, Boateng, & Lang, 2020) or found little to no impact of legalization on crime (Lu et al., 2019). Given the public concern about legalization’s impact on crime, more studies based on rigorous research designs are needed to further examine the implications of recreational marijuana legalization for public safety.

The available limited prior studies on this issue have predominantly focused on Colorado and/or Washington State—the two states that first legalized recreational marijuana in the U.S. This is reasonable considering that an examination of a relatively longer post-legalization period would be helpful for revealing the prospective effects of legalization on such outcome variables related to public safety as crime rates and crime clearance rates. However, given that more states have legalized following Colorado and Washington State, and some of them have also implemented their recreational marijuana laws for a few years, it is now necessary to expand the examination to other states. For instance, although six years have passed since the passage of the recreational marijuana law (RML) in late 2014 in Oregon, it is difficult to find studies examining how legalization has affected crime in this state.

In effect, the impact of marijuana legalization on crime may vary across legalized states based on differential marijuana-related laws and regulations. For instance, although Colorado (CO), Washington State (WA), and Oregon (OR) have overall legalized marijuana for recreational purposes including production, possession, and sale, these three states differ in certain important aspects associated with the regulation of recreational marijuana. Specifically, for example, while CO and OR allow their residents over 21 to grow several marijuana plants for personal recreational use, it remains illegal in WA to grow recreational marijuana on private property for personal use. Also, these states differ in terms of the amount of marijuana concentrates that people can purchase – the maximum limits for CO, OR, and WA are 8 g, 7 g, and 5 g, respectively. Given these variations in marijuana-related policies across the legalized states, it is worthwhile to extend this line of research and examine how recreational marijuana legalization affects crime in states that have recently legalized marijuana such as Oregon. Moreover, prior relevant research has usually focused on a certain city or specific areas, which may limit generalizability of their findings (Brinkman & Mok-Lamme, 2019; Hao & Cowan, 2020; Hughes et al., 2019). It would be more informative to policy makers and the public to examine large geographical areas within a legalized state, thus examining the impact of recreational marijuana legalization on public safety for an entire state.

This study intends to address these important knowledge gaps. Specifically, it is a large-scale study using county-level Uniform Crime Report data that examines changes in rates of a wide range of serious crimes, including violent crime, property crime, robbery, aggravated assault, larceny, motor-vehicle theft, and burglary, in Oregon, relative to the 19 states1 that have not legalized marijuana for recreational or medical purposes (until 2017). In addition, as a robustness check of the results, we have also conducted analyses using a control group consisting of five states2 in which only medical marijuana are legal during the study period. This study not only offers an extended period of observation spanning from 2007 to 2017, but also involves analyses of crime data for all counties in the 25 states examined.

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Perspectives on the relevance of marijuana legalization to crime

Although there seems to be a trend toward marijuana legalization, as manifested by the majority of U.S. states that have legalized medical marijuana and the increasing number of states legalizing recreational marijuana, the issue still generates controversy (Freisthler, Gaidus, Tam, Ponicki, & Gruenewald, 2017). As mentioned above, opposing perspectives exist regarding legalization’s implications for public safety, and, central to this discussion, is its impact on crime. This is not surprising

Empirical evidence on the impact of marijuana legalization on crime

In the last two decades, there has been growing scholarly attention paid to the impact of marijuana legalization on crime (Brinkman & Mok-Lamme, 2019; Chu & Townsend, 2019; Contreras, 2016; Dragone et al., 2019; Freisthler et al., 2017; Freisthler, Ponicki, Gaidus, & Gruenewald, 2016; Kepple & Freisthler, 2012; Hao & Cowan, 2020; Hughes et al., 2019; Lu et al., 2019; Makin et al., 2019; Morris et al., 2014; Shepard & Blackley, 2016; Wu et al., 2020). Given that the legalization of marijuana for


As the purpose of this study is to explore the potential effects of recreational marijuana legalization on crime in Oregon counties, and this examination involves the comparison of crime trends between Oregon and the 19 states that have not legalized marijuana for recreational or medical purposes, we used county-level crime data for Oregon and these non-legalized states. In addition, as a robustness check of the results, we also used county-level crime data for the five medical marijuana-only


Table 2 presents the effects of marijuana legalization on specific crime rates in Oregon using the control group of 19 non-legalized states. As it shows, recreational marijuana legalization in OR has led to significant increases in the rates of not only property crime overall (p = .021), but also subtypes of crimes such as burglary (p = .020) and motor vehicle theft (p = .000) in the state, relative to the non-legalized states following legalization in OR. In addition, an increase, having


We used a rigorous quasi-experimental research design and county-level crime data to examine the impact of marijuana legalization on serious crimes as measured by the UCR in Oregon. We examined violent and property crime in general, and a set of specific crimes such as burglary, larceny, motor vehicle theft, robbery, and aggravated assault. Overall, the results reveal that legalization in Oregon has likely led to substantial increases in most crime types examined relative to states that have


The results of this study provide evidence suggesting a crime-exacerbating effect of recreational marijuana legalization, manifested by substantial increases in a variety of major crimes as measured by the UCR in Oregon counties relative to non-legalized states following legalization. Given that the findings of this study are inconsistent with those obtained in some prior studies focusing on Colorado and Washington State, this suggests a need to examine legalization impact with consideration of