Anthony A. Braga

Problem-Oriented Policing, Deterrence, and Youth Violence: An Evaluation of Boston's Operation Ceasefire

Operation Ceasefire is a problem-oriented policing intervention aimed at reducing youth homicide and youth firearms violence in Boston. It represented an innovative partnership between researchers and practitioners to assess the citys youth homicide problem and implement an intervention designed to have a substantial near-term impact on the problem. Operation Ceasefire was based on the “pulling levers” deterrence strategy that focused criminal justice attention on a small number of chronically offending gang-involved youth responsible for much of Bostons youth homicide problem. Our impact evaluation suggests that the Ceasefire intervention was associated with significant reductions in youth homicide victimization, shots-fired calls for service, and gun assault incidents in Boston. A comparative analysis of youth homicide trends in Boston relative to youth homicide trends in other major U.S. and New England cities also supports a unique program effect associated with the Ceasefire intervention.

The Effects of Hot Spots Policing on Crime: An Updated Systematic Review and Meta-Analysis

In recent years, crime scholars and practitioners have pointed to the potential benefits of focusing police crime prevention efforts on crime places. Research suggests that there is significant clustering of crime in small places or “hot spots.” A number of researchers have argued that crime problems can be reduced more efficiently if police officers focused their attention to these deviant places. In this article, we update and improve upon a previously completed Campbell Collaboration systematic review of the effects of hot spots policing and crime. Meta-analyses were used to determine the size, direction, and statistical significance of the overall impact of hot spots policing strategies on crime. The results of our research suggests that hot spots policing generates small but noteworthy crime reductions, and these crime control benefits diffuse into areas immediately surrounding targeted crime hot spots. Our analyses find that problem-oriented policing interventions generate larger mean effect sizes when compared to interventions that simply increase levels of traditional police actions in crime hot spots. We also find that only a small number of studies examine the impacts of hot spots policing on police-community relations. The extant research on this topic, however, suggests that community members have positive reactions to these focused policing actions.

The Effects of Focused Deterrence Strategies on Crime A Systematic Review and Meta-Analysis of the Empirical Evidence

Objective. Focused deterrence strategies are increasingly being applied to prevent and control gang and group-involved violence, overt drug markets, and individual repeat offenders. Given the growing popularity of this approach, a systematic review and meta-analysis of the extant evaluation evidence is needed to determine the crime reduction benefits of the approach. Methods. Our examination of the effects of focused deterrence strategies on crime followed the systematic review protocols and conventions of the Campbell Collaboration. As a preliminary examination of the effects of focused deterrence strategies on crime, the authors used a vote counting procedure. In our closer examination of program effects, meta-analyses were used to determine the size, direction, and statistical significance of the overall impact of focused deterrence strategies on crime. Results. We identified 10 quasi-experimental evaluations and 1 randomized controlled trial. Our meta-analysis suggests that focused deterrence strategies are associated with an overall statistically significant, medium-sized crime reduction effect. However, the strongest program effect sizes were generated by evaluations that used the weakest research designs. Conclusion. The authors conclude that this approach seems very promising in reducing crime but a more rigorous body of evaluation research needs to be developed. While the results of this review are very supportive of deterrence principles, the authors believe that other complementary crime control mechanisms are at work in the focused deterrence strategies described here that need to be highlighted and better understood.

The Corner and the Crew: The Influence of Geography and Social Networks on Gang Violence

Nearly a century of empirical research examines how neighborhood properties influence a host of phenomena such as crime, poverty, health, civic engagement, immigration, and economic inequality. Theoretically bundled within these neighborhood effects are institutions’ and actors’ social networks that are the foundation of other neighborhood-level processes such as social control, mobilization, and cultural assimilation. Yet, despite such long-standing theoretical links between neighborhoods and social networks, empirical research rarely considers or measures dimensions of geography and social network mechanisms simultaneously. The present study seeks to fill this gap by analyzing how both geography and social networks influence an important social problem in urban America: gang violence. Using detailed data on fatal and non-fatal shootings, we examine effects of geographic proximity, organizational memory, and additional group processes (e.g., reciprocity, transitivity, and status seeking) on gang violence in Chicago and Boston. Results show adjacency of gang turf and prior conflict between gangs are strong predictors of subsequent gang violence. Furthermore, important network processes, including reciprocity and status seeking, also contribute to observed patterns of gang violence. In fact, we find that these spatial and network processes mediate racial effects, suggesting the primacy of place and the group in generating gang violence.

Testing for Structural Breaks in the Evaluation of Programs

A standard methodology in program evaluation is to use time series variation to compare pre- and post-program outcomes. However, when the timing of a break in a statistical relationship can be determined only by looking at the data, then the usual distribution of the test statistic which assumes exogenous timing of the break is no longer valid. Tests for parameter instability provide a flexible framework for testing a range of hypotheses commonly posed in program evaluation. These tests help pinpoint the timing of maximal break and provide a valid test of statistical significance. These tests are particularly useful when the start date of the intervention and any effect is unclear and possibly endogenous due to implementation lags. A test of parameter instability is applied to the evaluation of the Boston Gun Project, a comprehensive effort to reduce youth homicide in Boston in the mid 1990s. The dynamics of gang violence meant that no parts of the city could be used as reasonable comparison sites, and thus time series analysis is the only feasible means of evaluating the program impact. The statistical procedure identifies a statistically significant discontinuity in youth homicide incidents shortly after the intervention was unveiled. The intervention was associated with about a 60 percent decline in youth homicide.

The Relevance of Micro Places to Citywide Robbery Trends: A Longitudinal Analysis of Robbery Incidents at Street Corners and Block Faces in Boston:

Robbery, and the fear it inspires, has a profound effect on the quality of life in certain urban neighborhoods. Recent advances in criminological research suggest that there is significant clustering of crime in micro places, or ‘‘hot spots,’’ that generate a disproportionate amount of criminal events in a city. In this article, the authors use growth curve regression models to uncover distinctive developmental trends in robbery incidents at street segments and intersections in Boston over a 29-year period. The authors find that robberies are highly concentrated at a small number of street segments and intersections rather than spread evenly across the urban landscape over the study time period. Roughly 1 percent and 8 percent of street segments and intersections in Boston are responsible for nearly 50 percent of all commercial robberies and 66 percent of all street robberies, respectively, between 1980 and 2008. Our findings suggest that citywide robbery trends may be best understood by examining micro-level trends at a relatively small number of places in urban environments.

Stress and Hardship after Prison.

The historic increase in U.S. incarceration rates made the transition from prison to community common for poor, prime-age men and women. Leaving prison presents the challenge of social integration—of connecting with family and finding housing and a means of subsistence. The authors study variation in social integration in the first months after prison release with data from the Boston Reentry Study, a unique panel survey of 122 newly released prisoners. The data indicate severe material hardship immediately after incarceration. Over half of sample respondents were unemployed, two-thirds received public assistance, and many relied on female relatives for financial support and housing. Older respondents and those with histories of addiction and mental illness were the least socially integrated, with weak family ties, unstable housing, and low levels of employment. Qualitative interviews show that anxiety and feelings of isolation accompanied extreme material insecurity. Material insecurity combined with the adjustment to social life outside prison creates a stress of transition that burdens social relationships in high-incarceration communities.

Underground Gun Markets

This paper provides an economic analysis of underground gun markets drawing on interviews with gang members, gun dealers, professional thieves, prostitutes, police, public school security guards and teens in the city of Chicago, complemented by results from government surveys of recent arrestees in 22 cities plus administrative data for suicides, homicides, robberies, arrests and confiscated crime guns. We find evidence of considerable frictions in the underground market for guns in Chicago. We argue that these frictions are due primarily to the fact that the underground gun market is both illegal and %u201Cthin%u201D -- the number of buyers, sellers and total transactions is small and relevant information is scarce. Gangs can help overcome these market frictions, but the gang%u2019s economic interests cause gang leaders to limit supply primarily to gang members, and even then transactions are usually loans or rentals with strings attached.

Hot spots policing effects on crime

5 Background 5 Objectives 5 Search Strategy 5 Selection Criteria 5 Data collection and Analysis 6 Results 6 Authors’ Conclusions 6

Measuring and improving police performance: the lessons of Compstat and its progeny

Police performance measurement systems based on traditional indicators, such as arrest rates and response times, prevent police organizations from moving towards a strategy of community problem solving as there is no way to hold police departments externally accountable for addressing community concerns and no way to hold particular officers internally accountable for engaging community problem‐solving activities. In the absence of relevant measurement systems, police executives experience difficulty motivating their managers and line‐level officers to change their approach towards policing. A number of departments have made considerable progress in developing performance measurement systems that both address community concerns and drive their organizations towards a community problem‐solving strategy. This paper argues why police executives would want to measure performance, describes how measurement is important in driving organizational change, discusses what police departments should be measuring, and presents an exploratory qualitative analysis of the mechanisms at work in the New York Police Department’s Compstat and its application in six other police departments.