Objectives: Recent work has debated which geographic scale is most relevant to understanding the clustering of crime and disorder across a city. This study introduces nested Gini coefficients that help answer this question by disentangling concentrations of crime at multiple scales in a single city while also controlling for artifacts of arithmetic and urban form. Methods: The study examines six indices of crime and disorder drawn from requests for government services received by the City of Boston in 2011 for addresses (N = 98,355) nested in street segments (N = 13,048) nested in census tracts (N = 178). Nested Gini coefficients assessed the average concentration at each level independent of the higher geographic unit (e.g., the streets of a single tract). Results: Concentrations were greatest at addresses, then at streets, and then at tracts. Compared to whole-city calculations, they showed equal or greater levels of concentration of crime and disorder for addresses, but lower concentrations for streets. Controlling for the number of locations on a street or in a tract also markedly diminished concentrations. Conclusions: The findings indicate a continued need to explain concentrations of crime, especially at localized geographic scales.

中文翻译：

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行动无处不在，但在更局限的空间尺度上发挥更大作用

目标：最近的工作辩论了哪个地理范围与了解整个城市的犯罪和混乱的集群最相关。这项研究引入了嵌套的基尼系数，可以通过解开单个城市中多个级别的犯罪集中度，同时控制算术和城市形式的假象来帮助回答这个问题。方法：这项研究检查了波士顿市在2011年收到的政府服务请求中涉及的犯罪和乱序的六个指标，这些地址分别嵌套在街道段（N = 13,048）和人口普查区域（N = 178）中，地址（N = 98,355） 。嵌套的基尼系数评估了每个级别的平均浓度，而与较高的地理单位（例如，单个区域的街道）无关。结果：在地址上，然后在街道上，然后在地段，浓度最大。与整个城市的计算相比，他们对地址和犯罪的集中程度处于相同或较高的水平，而对街道的集中度则较低。控制街道或区域中的位置数量也明显减少了浓度。结论：研究结果表明，仍然需要解释犯罪的集中性，特别是在局部地理范围内。