Both authors are former pre-doctoral fellows of the National Consortium on Violence Research. This material is based upon work supported by the National Science Foundation under Grant No. SES-0215551 to the National Consortium on Violence Research. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. The initial trajectory analysis portion of this paper was presented at the 2002 NCOVR summer workshop in St. Augustine, FL. An earlier draft of this paper received 2nd place in the 2003 American Society of Criminology Gene Carte Student Paper competition and was presented at the 2003 ASC conference in Denver, CO. We would like to thank Rosemary Gartner, Breda McCabe, David McDowall, Daniel Nagin, George Tita and anonymous reviewers for their feedback on this manuscript. Please direct all correspondence concerning this article to Elizabeth Griffiths, Department of Sociology and Centre of Criminology, University of Toronto, 725 Spadina Ave, Toronto Ontario, M5S 2J4, Canada; email: email@example.com.
COMMUNITIES, STREET GUNS AND HOMICIDE TRAJECTORIES IN CHICAGO, 1980–1995: MERGING METHODS FOR EXAMINING HOMICIDE TRENDS ACROSS SPACE AND TIME*
Article first published online: 7 MAR 2006
Volume 42, Issue 4, pages 941–978, November 2004
How to Cite
GRIFFITHS, E. and CHAVEZ, J. M. (2004), COMMUNITIES, STREET GUNS AND HOMICIDE TRAJECTORIES IN CHICAGO, 1980–1995: MERGING METHODS FOR EXAMINING HOMICIDE TRENDS ACROSS SPACE AND TIME. Criminology, 42: 941–978. doi: 10.1111/j.1745-9125.2004.tb00541.x
- Issue published online: 7 MAR 2006
- Article first published online: 7 MAR 2006
We merge Exploratory Spatial Data Analysis (ESDA) and a semi-parametric, group-based trajectory procedure (TRAJ) to classify communities in Chicago by violence trajectories across space. Total, street gun and other weapon homicide trajectories are identified across 831 census tracts between 1980 and 1995. We find evidence consistent with a weapon substitution effect in violent neighborhoods that are proximate to one another, a defensive diffusion effect of exclusively street gun-specific homicide increases in neighborhoods bordering the most violent areas, and a spatial decay effect of temporal homicide trends in which the most violent areas are buffered from the least violent by places experiencing mid-range levels of lethal violence over time. In merging these two methods of data analysis, we provide a more efficient way to describe both spatial and temporal trends and make significant advances in furthering applications of space-time methodologies.