Journal of Quantitative Criminology 26(2)

Project Safe Neighborhoods and Violent Crime Trends in US Cities: Assessing Violent Crime Impact
Edmund F. McGarrell, Nicholas Corsaro, Natalie Kroovand Hipple and Timothy S. Bynum

Since the mid-1990s, a number of initiatives intended to address gang, gun and drug-related violence have arisen and demonstrated promise in reducing levels of violent crime. These initiatives have employed some combination of focused deterrence and problem-solving processes. These strategies formed the basis for Project Safe Neighborhoods (PSN), a national program implemented by the Department of Justice and coordinated by US Attorneys’ Offices. This paper is an initial attempt to assess the potential impact of the nationally implemented PSN initiative through an analysis of violent crime trends in all US cities with a population of 100,000 or above. While a number of site specific studies exist examining the potential impact of locally implemented PSN programs, to date no national-level study has examined whether PSN may have had an impact on violent crime trends. Cities included in the current study are distinguished on the basis of whether they were considered a treatment city by the PSN task force and by the level of implementation dosage of the PSN program. This allowed a comparison of 82 treatment cities and 170 non-treatment cities as well as a variable of dosage level. Hierarchical Generalized Linear Models (HGLM) were developed that controlled for other factors that may have affected the level of violent crime across the sample of cities. The results suggested that PSN treatment cities in higher dosage contexts experienced statistically significant, though modest, declines in violent crime whereas non-target cities and low dosage contexts experienced no significant changes in violent crime during the same period. The limitations of this initial analysis are noted but the evidence seems to suggest that the multi-agency, focused deterrence, problem solving approach holds promise for reducing levels of violent crime. At a minimum, these findings call for continued programmatic experimentation with data-driven, highly focused, deterrence-based violence reduction strategies.

A Multilevel Test of Minority Threat Effects on Sentencing
Xia Wang and Daniel P. Mears

Prior studies of criminal sanctioning have focused almost exclusively on individual-level predictors of sentencing outcomes. However, in recent years, scholars have begun to include social context in their research. Building off of this work—and heeding calls for testing the racial and ethnic minority threat perspective within a multilevel framework and for separating prison and jail sentences as distinct outcomes—this paper examines different dimensions of minority threat and explores whether they exert differential effects on prison versus jail sentences. The findings provide support for the racial threat perspective, and less support for the ethnic threat perspective. They also underscore the importance of testing for non-linear threat effects and for separating jail and prison sentences as distinct outcomes. We discuss the findings and their implications for theory, research, and policy.

Statistical Inference After Model Selection
Richard Berk, Lawrence Brown and Linda Zhao

Conventional statistical inference requires that a model of how the data were generated be known before the data are analyzed. Yet in criminology, and in the social sciences more broadly, a variety of model selection procedures are routinely undertaken followed by statistical tests and confidence intervals computed for a “final” model. In this paper, we examine such practices and show how they are typically misguided. The parameters being estimated are no longer well defined, and post-model-selection sampling distributions are mixtures with properties that are very different from what is conventionally assumed. Confidence intervals and statistical tests do not perform as they should. We examine in some detail the specific mechanisms responsible. We also offer some suggestions for better practice and show though a criminal justice example using real data how proper statistical inference in principle may be obtained.

The Effects of Multiple Dimensions of Residential Segregation on Black and Hispanic Homicide Victimization
Min Xie

Past research examining the association between residential segregation and homicide victimization has often considered only one dimension of segregation, and the literature that does use a multidimensional approach has not presented a uniform set of findings. The majority of the studies have focused on the experiences of Blacks, while overlooking the possibility that the differences between the structure of Black and Hispanic communities may alter the conclusions for Hispanics. In this study, we argue that in order to understand the mechanisms underlying the effects of segregation on homicide, we need to understand the multidimensional structure of Black and Hispanic segregation, and examine whether the relationship between segregation and homicide differs for Blacks and Hispanics. Using 2000 census data and homicide data from the National Vital Statistics System (1999–2001) for U.S. metropolitan areas, we identify two empirically distinct superdimensions of segregation (group separateness and centralized concentration), both of which have a substantial positive and statistically significant impact on homicide victimization for both Blacks and Hispanics.

The Impact of Imprisonment on Marriage and Divorce: A Risk Set Matching Approach
Robert Apel, Arjan A. J. Blokland, Paul Nieuwbeerta and Marieke van Schellen

Marriage has a prominent place in criminological theory and research as one institution that has the potential to genuinely foster desistance from a criminal career. Mass imprisonment policies in the United States and elsewhere, therefore, pose a potential threat of increased crime if they impede the ability of ex-prisoners to reintegrate into society by stigmatizing them and limiting their chances in the marriage market. We use a long-term study of a conviction cohort in The Netherlands to ascertain the effect that first-time imprisonment has on the likelihood of marriage and divorce. The results suggest that the effect of imprisonment on the likelihood of marriage (among unmarried offenders) is largely a selection artifact, although there is very weak evidence for a short-lived impact that does not persist past the first year post-release. This is interpreted as a residual incapacitation effect. On the other hand, the results strongly suggest that the experience of incarceration leads to a substantially higher divorce risk among offenders who are married when they enter prison.

Journal of Quantitative Criminology, June 2010: Volume 26, Issue 2