An Ecological Study of the Location of Gang “Set Space”

Previous gang research has focused primarily on the attributes of individuals who join gangs. This ecolog-ical study of violent urban youth gangs examines the social, economic, and physical organization of places where gangs locate. Our goal is to understand those features of communities that either facilitate the formation of gangs or insulate an area from gang formation. By interviewing gang members and having them map places where they came together as a sociological group to “hang out, ” we study what we label as the “set space ” of gangs. Our study is analogous to criminological studies of where criminal acts occur rather than of the factors that lead an individual to commit criminal acts. This study indicates that gang set space is usually a very small geographic area, much smaller than neighborhoods or even census tracts. A probability (logit) model estimates the influence of various local area attributes on the presence of violent youth gangs in census block groups. Diminished social control—in the absence of capable guardians and physical abandonment of place—and underclass features increase the likelihood of observing violent youth gangs hanging out in a particular area. The 1990s saw renewed interest in quantitatively oriented, neighborhood-based studies of delinquency, violence, and other problem behaviors. In a review of this literature, Robert J. Sampson, Jeffery D. Morenoff, and Thomas Gannon-Rowley (2002) identified 40 published studies that explicitly examined both the social processes and mechanisms (i.e., “neighbor-