New Approach to Evaluating Supplementary Homicide Report (SHR) Data Imputation, 1990-1995

The purpose of the project was to learn more about patterns of homicide in the United States by strengthening the ability to make imputations for Supplementary Homicide Report (SHR) data with missing values. Supplementary Homicide Reports (SHR) and local police data from Chicago, Illinois, St. Louis, Missouri, Philadelphia, Pennsylvania, and Phoenix, Arizona, for 1990 to 1995 were merged to create a master file by linking on overlapping information on victim and incident characteristics. Through this process, 96 percent of the cases in the SHR were matched with cases in the police files. The data contain variables for three types of cases: complete in SHR, missing offender and incident information in SHR but known in police report, and missing offender and incident information in both. The merged file allows estimation of similarities and differences between the cases with known offender characteristics in the SHR and those in the other two categories. The accuracy of existing data imputation methods can be assessed by comparing imputed values in an "incomplete" dataset (the SHR), generated by the three imputation strategies discussed in the literature, with the actual values in a known "complete" dataset (combined SHR and police data). Variables from both the Supplemental Homicide Reports and the additional police report offense data include incident date, victim characteristics, offender characteristics, incident details, geographic information, as well as variables regarding the matching procedure.

本项目旨在通过提升对存在缺失值的补充凶杀报告（Supplementary Homicide Report, SHR）数据的插补能力，深入探究美国凶杀案件的案发模式。研究整合了1990至1995年间，取自美国伊利诺伊州芝加哥市、密苏里州圣路易斯市、宾夕法尼亚州费城以及亚利桑那州菲尼克斯市的补充凶杀报告数据与当地警方警务数据，通过匹配受害者与案件特征的重叠字段构建主数据集。经此匹配流程，补充凶杀报告中96%的案件可与警方档案中的案件完成关联。该数据集涵盖三类案件的相关变量：一是补充凶杀报告中信息完整的案件；二是补充凶杀报告缺失作案者与案件细节信息，但警方报告中该类信息完整的案件；三是补充凶杀报告与警方报告均缺失作案者与案件细节信息的案件。该整合数据集可用于对比分析补充凶杀报告中作案者特征已知的案件，与其余两类案件之间的异同。现有数据插补方法的准确性可通过如下方式评估：将文献中提及的三类插补策略生成的"不完备"数据集（即补充凶杀报告数据）中的插补值，与已知"完备"数据集（即整合后的补充凶杀报告与警方数据）中的真实值进行对比。补充凶杀报告与附加警方案件数据中的变量涵盖：案发日期、受害者特征、作案者特征、案件细节、地理信息，以及与匹配流程相关的变量。