Homicide in Urban America: 1950-1980

这个项目解决了城市凶杀率的原因。PI将从四个相互竞争的理论角度提出假设：(1)暴力亚文化，即谋杀率高的地区的特征是更高的预期（或可容忍）暴力水平；(2)社会经济，认为暴力是物质匮乏的结果，例如与抢劫有关的杀人；(3)惩罚和威慑，认为谋杀率随着惩罚的确定性和严厉程度的变化而上升和下降；(4)生活模式，这是一个更复杂的概念，涉及动机、机会和缺乏有效的监护人，如警察。每种理论都有强有力的支持者，但很少有数据被用来比较每种理论的预测成功率。缺乏经验验证的部分原因是难以获得纵向数据。该项目使用30年时间跨度的匹配区域来估计包含所有四种理论假设的模型。结果应该允许评估每个理论中指定的因素的贡献，并理解每个理论过程最有可能出现的条件。

This project addresses causes of urban homicide rates. The PI will draw hypotheses from four competing theoretical perspec- tives: (1) Subculture of violence, the idea that areas with high homicide rates are characterized by a higher expected (or tolera- ted) level of violence; (2) Socioeconomic, the idea that violence is a consequence of material deprivation, such as homicides connected with robbery; (3) Punishment and deterrence, the idea that homicide rates rise and fall with changes in certainty and severity of punishment; (4) Life patterns, a more complex idea involving motivation, opportunities, and lack of effective guardians such as police. Each theory has strong proponents, but data seldom have been applied to compare the predictive success of each. Part of the reason for the lack of empirical verifica- tion has been the difficulty of obtaining longitudinal data. This project uses matched areas, with a 30-year time span, to estimate a model incorporating hypotheses from all four theories. The results should permit assessment of contribution of the factors specified in each theory, and understanding conditions under which each theoretical process is most likely to appear.