Association for Public Policy Analysis & Management

The societal costs of illicit drugs parallel those associated with serious health problems such as diabetes and obesity, with recent estimates placing drug-related costs at around $193 million a year (National Drug Intelligence Center, 2011). One such consequence of illicit drugs may be elevated rates of crime. The relationship between drugs and crime came to the forefront of criminological thought in the wake of the surge in serious crime—in particular, violent crime—during the late 1980s and early 1990s in U.S. central cities. Although scholars predicted even greater increases in serious crime in the early and mid-1990s, rates of serious crime actually plunged. This crime drop led scholars to provide explanations for such a drop, with drug activity—broadly defined as all activity “related to the production, distribution, purchase and use of illegal substances” (Freisthler, Lascala, Gruenewald, & Treno, 2005, p. 683)—serving as one of the more plausible explanations. Drug market explanations for the rise, and subsequent drop, in violence in U.S. inner cities, according to Blumstein and Rosenfeld (1998), make causal sense insofar as “[r]ates of serious violence, including homicide went up during the rise phase of the crack epidemic and have been dropping during the decline phase” (p. 1209).

With that being said, although Goldstein's (1985) seminal piece on the drugs-crime nexus has been a mainstay in the drugs and crime literature, communities and crime studies in criminology have largely neglected and left under-theorized how drugs and crime may be related across time and space. While studies examining the drugs-crime nexus have found a robust relationship at the city-level, few have examined whether such a relationship holds up at a smaller geographic scale. So, such studies may lack a theoretical focus on how drug activity may relate to crime and place. Still further, the few studies examining whether drug activity and neighborhood crime are related have been cross-sectional, thereby limiting inferences regarding the causal nature of the ecological relationship between drugs and crime. Accordingly, these studies have also not theorized the temporal scaling underpinning the drug activity and neighborhood crime association. And, equally important, researchers have yet to assess whether the larger social context moderates such a relationship.

We build on the literature on the drugs-crime nexus in the following ways. Using Uniform Crime Reporting (UCR) Part I and Part II address-level incident data provided by the Miami-Dade Police Department, we estimate longitudinally the monthly and cumulative lagged impact that drug activity has on crime rate change in census blocks in the largely unincorporated areas of Miami-Dade County, Florida. What's more, we assess whether the assaultive violence produced in blocks with more drug activity spills over into nearby blocks, implying a spatial diffusion process, which heretofore has been unexplored—and hence, untheorized—in prior literature on the drugs-crime nexus. Moreover, we assess whether the larger social context moderates the drugs-crime relationship. In light of our findings, implications and avenues for future research will be discussed.