DOI: 10.3886/icpsr04079.v1
title: Spatial Analysis of Rare Crimes: Homicides in Chicago, Illinois, 1989-1991
title: Version 1

description: This project's main goal was to develop an analytical framework that could be used for analysis of rare crimes observed at local (intra-city) levels of geographic aggregation. To demonstrate the application of this framework to a real-world issue, this project analyzed the occurrence of different types of homicide at both the census tract and neighborhood cluster level in Chicago. Homicide counts for Chicago's 865 census tracts for 1989-1991 were obtained from HOMICIDES IN CHICAGO, 1965-1995 (ICPSR 6399), Part 1: Victim Level Data. The types of homicide examined were gang-related, instrumental, family-related expressive, known person expressive, stranger expressive, and other. Demographic and socioeconomic data at the census tract level for the year 1990 were obtained from the Neighborhood Change Database (NCDB) at the Urban Institute. Part 1 contains these data, as initially obtained, at the census tract level. Part 2 contains an aggregated version of the same data for Chicago's 343 neighborhood clusters as defined by the Project on Human Development in Chicago's Neighborhoods.
description: This project's main goal was to develop an analytical framework that could be used for analysis of rare crimes observed at local (intra-city) levels of geographic aggregation. To demonstrate the application of this framework to a real-world issue, this project analyzed the occurrence of different types of homicide at both the census tract and neighborhood cluster level in Chicago. For the years of the study Chicago had 865 census tracts and 343 neighborhood clusters as defined by the Project on Human Development in Chicago's Neighborhoods. The types of homicide examined were gang-related, instrumental, family-related expressive, known person expressive, stranger expressive, and other. The study asked (1) How do the socio-economic and demographic characteristics in an area affect the number of homicides that a community can expect to experience? (2) To what extent are these links specific to homicide type? and (3) Does the strength of these links depend on whether the census tract or neighborhood cluster is the geographic unit used in the analysis?
description: Homicide counts for Chicago's 865 census tracts for 1989-1991 were obtained from HOMICIDES IN CHICAGO, 1965-1995 (ICPSR 6399), Part 1: Victim Level Data. The homicides were originally classified into ten categories: gang-related, sexual assault, instrumental, spousal attack, child abuse, other family expressive, other known expressive, stranger expressive, other, and mystery. For the purposes of this study the sexual assault, child abuse, and other family expressive were collapsed into a family-related expressive category and homicides classified as sexual assault or mystery were added to the category called other. Demographic and socioeconomic data at the census tract level were obtained from the Neighborhood Change Database (NCDB) at the Urban Institute for the year 1990 (or as close as possible to it). Data in the NCDB are based on information gathered by the United States Census Bureau in its decennial censuses. Part 1 contains these data, as initially obtained, at the census tract level. Part 2 contains these data aggregated up to the neighborhood cluster level. The mapping of the census tracts to the relevant neighborhood clusters was obtained from staff at the Project on Human Development in Chicago's Neighborhoods and was used with their permission. Some census tracts had missing information for some of the demographic and socioeconomic variables. This project used simple mean imputations to replace missing values at the census tract level. Missing values for a variable in a given census tract were set equal to the mean of non-missing values for all census tracts in the same neighborhood cluster as the census tract missing the desired information. This resulted in a sample with no missing information at the census tract level. As a result, when aggregating to the neighborhood cluster level, no missing data imputations needed to be performed.
description: Part 1 contains the following information for each of Chicago's census tracts: counts of all homicides, gang-related homicides, instrumental homicides, family homicides, known person homicides, stranger homicides, other homicides, hispanics as a percentage of the population, blacks as a percentage of the population, percent of female-headed households with kids, unemployment rate, poverty rate, percent of nonfamily households, young males as a percentage of the population, residential stability, natural log of the population, and a resource deprivation index. There are also variables corresponding to each census tract that indicate which of the other census tracts it borders and its distance in miles from each of the other census tracts. Part 2 contains the same information at the neighborhood cluster level.
description: Response Rates: Not applicable
description: Presence of Common Scales: Measures of residential stability and resource deprivation are included in Parts 1 and 2.
description: inap.
description: Datasets: DS0: Study-Level Files DS1: Census Tract Level Data DS2: Neighborhood Cluster Level Data
description: Part 1: Chicago's 1990 census tracts. Part 2: Chicago's neighborhood clusters as defined by the Project on Human Development in Chicago's Neighborhoods. Smallest Geographic Unit: census tracts
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