A Sensitivity Analysis of Egocentric Measures of Peer Delinquency to Latent Homophily: A Research Note
Jacob T. N. Young
Objectives: Egocentric measures of peer delinquency, obtained through a census of a social network, have become the preferred operationalization for examining the relationships between social influence and delinquency. Studies regressing ego’s delinquency on the delinquency of nominated friend/s (i.e. alter/s) conclude that a statistically significant coefficient provides evidence of social influence. However, the inferences drawn from these studies may be biased by the introduction of artificial statistical dependence as a consequence of using social network data in a regression framework. Recent work (Shalizi and Thomas Sociol Methods Res 40:211–239, 2011) shows that latent homophily, or unmeasured confounding of observables, may lead to nonzero estimates of social influence, even if there is no causal significance. To examine this possibility, sensitivity analyses have been created (e.g. VanderWeele and Arah Epidemiology 22:42–52, 2011; VanderWeele Sociol Methods Res 40:240–255, 2011) to determine the robustness of an estimated coefficient to latent homophily. Methods: In this research note, I examine the robustness of estimates for social influence from two articles (Haynie Am J Sociol 106:1013–1057, 2001; Meldrum et al. J Res Crime Delinq 46:353–376, 2009) using egocentric measures of peer delinquency.Results: Findings indicate that for large, precise point estimates, highly improbable conditions are needed to explain away the effects of social influence. However, less precise point estimates (i.e. large standard errors) are more sensitive to latent homophily.Conclusions: The analyses indicate that studies using egocentric measures should conduct sensitivity tests, particularly when the estimated effect is weak and/or has a relatively large standard error. Scripts written in the free programming language R (R Core Team R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, 2012) are provided for researchers to conduct such analyses.
Risky Facilities: Crime Radiators or Crime Absorbers? A Comparison of Internal and External Levels of Theft
Kate Bowers
Objectives: To undertake the first exploration of the nature of the relationship between internal crime (those that happen within facilities) and external crime (those occurring outside but in the nearby locale of facilities). The following questions are addressed. Do those localities that suffer high volumes of crime internally within their facilities also suffer high levels of crime in their immediate external environment? How is this influenced by the distribution of internal theft across facilities? What are the likely mechanisms for any relationship found?Methods: Spatial regression is used to explore these relationships using data for 30,144 incidents of theft from a Metropolitan area of the UK arranged into small 50 × 50 m grid squares. Variables used in the analysis include counts of external and internal theft, counts of victimized and ‘risky’ facilities, indicators of land-use and a proxy for the on-street population.Results: There is found to be a strong positive relationship between internal and external theft that appears to be strengthened by the existence of facilities suffering particularly high crime volumes. Results suggest that internal theft problems precede external ones and that the physical concentration of chronically risky facilities is a particularly strong predictor of external theft problems.Conclusions: An argument is made that risky facilities act as crime ‘radiators’, causing crime in the immediate environment as well as internally. This has implications for crime prevention policy in terms of facility placement and management.
Partying, Cruising, and Hanging in the Streets: Gangs, Routine Activities, and Delinquency and Violence in Chicago, 1959–1962
Lorine A. Hughes & James F. Short
Objectives: Examine relationships between routine activities, character contests in the form of “signifying,” and general delinquency and fighting in a street gang context.Methods: Samejima’s (Estimation of latent ability using a response pattern of graded scores. Psychometrika monograph supplement 17. Psychometric Society, Richmond, VA, Retrieved 10 Aug 2011, from http://www.psychometrika.org/journal/online/MN17.pdf, 1969) graded response models and multilevel ordinal logistic regression models are estimated using data from Short and Strodtbeck (Group process and gang delinquency. University of Chicago Press, Chicago, 1965) study of street gangs in Chicago, 1959–1962. The primary sample consists of 490 boys representing 10 black gangs, 4 white gangs, 9 black lower-class groups, 4 white lower-class groups, 2 black middle-class groups, and 2 white middle-class groups.Results: Unstructured and unsupervised socializing with peers significantly increased the likelihood of delinquency among the boys and explained a significant portion of the group-level gang effect. In addition, the more time the boys spent hanging in the streets and attending parties, the more likely they were to participate in signifying, which, in turn, increased their risk of fighting.Conclusions: Findings provide evidence that gangs contribute to delinquency partly through their effect on the routine activities of members. Findings also suggest that signifying is an important mechanism by which unstructured and unsupervised socializing with peers leads to violence.
Immigration and the Changing Nature of Homicide in US Cities, 1980–2010
Graham C. Ousey & Charis E. Kubrin
Objectives: Previous research has neglected to consider whether trends in immigration are related to changes in the nature of homicide. This is important because there is considerable variability in the temporal trends of homicide subtypes disaggregated by circumstance. In the current study, we address this issue by investigating whether within-city changes in immigration are related to temporal variations in rates of overall and circumstance-specific homicide for a sample of large US cities during the period between 1980 and 2010.Methods: Fixed-effects negative binomial and two-stage least squares (2SLS) instrumental variable regression models are used to analyze data from 156 large US cities observed during the 1980–2010 period.Results: Findings from the analyses suggest that temporal change in overall homicide and drug homicide rates are significantly related to changes in immigration. Specifically, increases in immigration are associated with declining rates for each of the preceding outcome measures. Moreover, for several of the homicide types, findings suggest that the effects of changes in immigration vary across places, with the largest negative associations appearing in cities that had relatively high initial (i.e., 1970) immigration levels.Conclusions: There is support for the thesis that changes in immigration in recent decades are related to changes in rates of lethal violence. However, it appears that the relationship is contingent and varied, not general.
Counterterrorism and Radical Eco-Groups: A Context for Exploring the Series Hazard Model
Jennifer Varriale Carson
Objective: This study examines whether radical eco-groups have been deterred by legal sanctions. From a rational choice framework, I argue that members of these groups weigh costs and benefits. I measure an increase in costs, or an objective deterrence effect, through four federal sentencing acts targeted at reducing the criminal behavior of these groups [the tree-spiking clause of the Anti-Drug Abuse Act (ADA), the Animal Enterprise Protection Act (AEPA), the Anti-Terrorism and Effective Death Penalty Act (AEDPA), and the Animal Enterprise Terrorism Act (AETA)] and hypothesize that this legislation decreased the hazard of subsequent attacks.Methods: This research is a quasi-experimental design utilizing the 1,068 illegal incidents perpetrated in the name of the environment, animal, or both as extracted from the Eco-Incidents Database. Using series hazard modeling, I examine the time until the next incident, serious incident, and ideologically specific incident in relation to dummy variables operationalizing the enactment dates of the above legislation.Results: All in all, the results are somewhat consistent with a rational choice framework and my hypotheses. The ADA decreased the hazard of another attack (11 %) and environment-only attack (15 %), while at the same time increasing the hazard of a terrorist, damage, and animal-related attack. AETA decreased the hazard of all (47 %), damage (42 %), and the behavior it was aimed at, that of animal-only incidents (52 %). However, neither the AEPA, nor AEDPA had a significant effect on any of the outcomes.Conclusions: Overall, radical eco-groups were deterred by legal sanctions, but these findings are legislation and outcome specific in addition to including displacement effects.
Adverse Neighborhood Conditions and Sanction Risk Perceptions: Using SEM to Examine Direct and Indirect Effects
Byungbae Kim , Travis C. Pratt & Danielle Wallace
Objectives: The present study examines how individuals’ sanction risk perceptions are shaped by neighborhood context.Methods: Using structural equation modeling on data from waves 6 and 7 of the National Youth Survey, we assess the direct and indirect relationships between adverse neighborhood conditions and two dimensions of sanction risk perceptions: the certainty of punishment and perceived shame. In addition, the role of shame as a mediator between neighborhood context and certainty of punishment is also investigated.Results: The results indicate that adverse neighborhood conditions indirectly affect both forms of sanction risk perceptions, and additional results show that perceived shame fully mediates the effect of neighborhood conditions on perceptions of the certainty of punishment.Conclusions: The perceptual deterrence/rational choice perspective will need to be revised to accommodate more explicitly the role of neighborhood context in shaping sanction risk perceptions.
Quantifying the Exposure of Street Segments to Drinking Places Nearby
Elizabeth R. Groff
Objectives: Introduce and test the relative efficacy of two methods for modeling the impact of cumulative ‘exposure’ to drinking facilities on violent crime at street segments.Methods: One method, simple count, sums the number of drinking places within a distance threshold. The other method, inverse distance weighted count, weights each drinking place within a threshold based on its distance from the street segment. Closer places are weighted higher than more distant places. Distance is measured as the street length from a street segment to a drinking place along the street network. Seven distance thresholds of 400, 800, 1,200, 1,600, 2,000, 2,400 and 2,800 feet are tested. A negative binomial regression model controlling for socio-economic characteristics, opportunity factors and spatial autocorrelation is used to evaluate which of the measure/threshold combinations produce a better fit as compared to a model with no exposure measures.Results: Exposure measured as an inverse distance weighted count produces the best fitting model and is significantly related to violent crime at longer distances than simple count (from 400 to 2,800 feet). Exposure to drinking places using a simple count is significantly related to violent crime up to 2,000 feet. Both models indicate the influence of drinking places is highest at shorter distance thresholds.Conclusions: Both researchers and practitioners can more precisely quantify the influence of drinking places in multivariate models of street segment level violent crime by incorporating proximity in the development of a cumulative exposure measure. The efficacy of using exposure measures to quantify the influence of other types of facilities on crime patterns across street segments should be explored.
The Direct and Indirect Effects of Offender Drug Use on Federal Sentencing Outcomes
Cassia C. Spohn , Byungbae Kim , Steven Belenko & Pauline K. Brennan
Objectives: The federal sentencing guidelines constrain decision makers’ discretion to consider offenders’ life histories and current circumstances, including their histories of drug use and drug use at the time of the crime. However, the situation is complicated by the fact that judges are required to take the offender’s drug use into account in making bail and pretrial detention decisions and the ambiguity inherent in decisions regarding substantial assistance departures allows consideration of this factor. In this paper we build upon and extend prior research examining the impact of an offender’s drug use on sentences imposed on drug trafficking offenders.Methods: We used data from three U.S. District Courts and a methodologically sophisticated approach (i.e., path analysis) to test for the direct and indirect (i.e., through pretrial detention and receipt of a substantial assistance departure) effects of an offender’s drug use history and use of drug at the time of the crime, to determine if the effects of drug use varies by the type of drug, and to test for the moderating effect of type of crime. Results: We found that although the offender’s history of drug use did not affect sentence length, offenders who were using drugs at the time of the crime received longer sentences both as a direct consequence of their drug use and because drug use at the time of the crime increased the odds of pretrial detention and increased the likelihood of receiving a substantial assistance departure. We also found that the effects of drug use varied depending on whether the offender was using crack cocaine or some other drug and that the type of offense for which the offender was convicted moderated these relationships. Conclusions: Our findings illustrate that there is a complex array of relationships between drug use and key case processing decisions in federal courts.
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