The Action Is Everywhere,But Greater at More Localized Spatial Scales: Comparing Concentrations of Crime across Addresses,Streets,and Neighborhoods

Abstract

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.