The Spatial Extent of Criminogenic Places: A Changepoint Regression of Violence around Bars

Crime scientists have long known that crime clusters near certain places such as drinking establishments, although the spatial parameters of that clustering are less established. This article proposes a methodology to estimate a distance beyond which there is significantly less evidence of a correlation between locations and concentrations of crime. The technique uses changepoints derived from a segmented regression applied to spatial buffers emanating from around particular crime‐generating land uses. Geographic information system techniques are used to create a series of buffers to determine the density of crime around sites. A changepoint Poisson regression of the buffer midpoints is used to estimate the distance beyond which crime densities do not appear to decline significantly with increasing distance. A case study of violent crime around 1,282 bars in Philadelphia, Pennsylvania, for 2008 reveals that violence is highly clustered within 25.9 m (85 feet) then dissipates rapidly, a pattern that is not replicated using control sites (fire stations). This is an estimate of the spatial extent of violence around bars, and the technique could be used to estimate the extent of other crimes around a variety of crime‐generating locations. Expertos en el estudio del crimen saben desde hace tiempo que los delitos violentos se concentran cerca de algunos lugares tales como establecimientos de bebidas, aunque los parámetros espaciales de dichas aglomeraciones son menos conocidos. Este artículo propone una metodología para estimar la distancia máxima a partir de la cual hay significativamente menos evidencia de una correlación entre puntos de interés y las aglomeraciones de crimen. La técnica empleada utiliza puntos de cambio (changepoints) derivados de una regresión segmentada (segmented regression) aplicada a las zonas de amortiguamiento (buffers) generadas en torno a usos del suelo particulares asociados a delincuencia. Técnicas SIG (Sistema de Información Geográfica) son utilizadas para crear una serie de buffers y determinar la densidad de delitos en torno a la ubicación de cada establecimiento (bar). Una regresión Poisson de tipo changepoint de los puntos medios de los buffers es empleada para estimar la distancia a partir de la cual las densidades del crimen no disminuyen significativamente con la distancia. Un estudio de caso de los delitos violentos en torno a 1.282 bares en Filadelfia, Pennsylvania en 2008 revela que la violencia está muy concentrada dentro de un radio de 25.9 m (85 pies) y luego se disipa rápidamente, un patrón que no se replica cuando el análisis es aplicado a sitios de control (estaciones de bomberos). El resultado es una estimación de la extensión espacial de la violencia alrededor de bares y la conclusión que la técnica podría ser utilizada para estimar la extensión de otros delitos en torno a una gran variedad de lugares asociados con la generación de la delincuencia. 犯罪学家早已明晰犯罪集聚于某些特定区域（如酒吧）的周围,尽管较少地构建这类聚集的空间参数。本文提出了一种方法可估算在一定距离之外,区位与犯罪集聚程度间相关性呈显著减少的证据。将从分段回归中获得的变异点应用于犯罪发生地的空间缓冲区。地理信息系统（GIS）技术用于产生一系列缓冲区以确定地点周围的犯罪密度。缓冲区中点的变异点泊松回归用于估算超出犯罪密度区不呈现随距离增加而显著衰退的距离。本文以宾夕法尼亚州费城1282个酒吧周围暴力犯罪为案例进行研究,揭示出2008年暴力犯罪集聚于25.9m的范围内,并在该距离之外的迅速消失,而当控制点选为消防站时该格局不再出现。实验表明,这是一种估算酒吧暴力犯罪空间范围的方法,并且该技术可用于估算不同类型犯罪产生地的距离范围。     

Book Reviews and Short Notices

De Villiers, P., La Chienne qui miaule (Albin Michel, 1990), 219 pp., 85F., ISBN 2 226 04131 1

De Villiers, P., Notre Europe sans Maastricht (Albin Michel, 1992), 156 pp., 80F., ISBN 2 226 06135 5

De Villiers, P., Avant qu'il ne soit trop tard (Albin Michel, 1993), 244pp., 89F., ISBN 2 226 06159 2

De Villiers, P., La Société de connivence ou comment faire avaler des serpents à sonnette (Albin Michel, 1994), 181 pp., 89F., ISBN 2 226 06918 6

De Villiers, P., Dictionnaire du politiquement correct à la française (Albin Michel, 1996), 201 pp., 89F., ISBN 2 226 08555 6     

The Nature of Things: Dead Labor, Nonhuman Actors, and the Persistence of Marxism

This article is about the question of social agency in the animation of things , and about how this problematic has been conceptualized in Marxist and Actor-Network Theory (ANT) approaches to human–nature–technology relations. Notwithstanding many obvious differences, we note that each tradition was founded on a radical shift to a relational ontology, a world of relations and processes and not things-in-themselves, and that each has developed, partly as a consequence of this move, analytically useful ways of investigating and talking about the work that things do, or appear to do, in the world. By relating the ANT category of non-human actors to the Marxist concept of dead labor, and by revisiting Marx's own dialectics of technology as embodied in his figure of the "living machine" in Capital , we explore the different implications of these approaches for our understandings of the nature, materiality, and the efficacy of social agents. We argue that ANT's reconfiguration of agency as a collective social and technical process—a process wherein the "nonhuman" can have very real social effects—can be deepened and given some political efficacy only if we take seriously the ontological problems of causality, accountability, and the directedness of social relations (and things) which ANT, and its wider, still evolving ethos among the social sciences and cultural studies, would have us forestall.