At the community level, a range of factors appears to be related to high levels of violence, consistent with the previously introduced concept of the contagion of violence. These include high rates of residential mobility, social isolation, unemployment, and illicit drug trafficking. For example, increased firearm violence has been associated with drug markets (Blumstein and Cork, 1996; Goldstein, 1985; Kennedy et al., 1996). This prevalence could be a consequence of drug dealers carrying guns for self-defense against thieves or other adversaries who are likely to be armed. Furthermore, in communities with street drug markets, especially those where such markets are ubiquitous, individuals not involved in the drug markets have similar incentives for possessing guns (Blumstein, 1995; Blumstein and Cork, 1996).
With regard to exposure to violence, “the burden of neighborhood risk falls unambiguously on minorities” (Zimmerman and Messner, 2013, p. 441), contributing to observed racial and ethnic disparities. These disparities, however, are largely accounted for by family/individual factors (lower levels of household socioeconomic status, higher rates of violent peer exposure and previous violent behavior) and neighborhood risk factors (high levels of concentrated disadvantage, deficiency of youth services) (Zimmerman and Messner, 2013). Additionally, low collective efficacy (defined as “social cohesion among neighbors combined with their willingness to intervene on behalf of the common good” [Sampson et al., 1997, p. 918]), is negatively associated with perceived violence, victimization, and homicide (Sampson et al., 1997). In turn, “concentrated disadvantage, immigrant concentration, and residential instability explain most of the variation” (Sampson et al., 1997, p. 922) (70 percent) in measures of collective efficacy. Much of the racial variation (more than 60 percent) in perpetration of violence “is explained by immigration status, marriage, length of residence, verbal/reading ability, impulsivity, and neighborhood context” (Sampson et al., 2005, p. 231), with neighborhood context being the most important (Sampson et al., 2005). Diminished economic opportunities, high concentrations of impoverished residents, high levels of transiency, high levels of family disruption, low levels of community participation, and socially disorganized neighborhoods are risk factors for youth violence overall.