An Institutionalization Effect: The Impact of Mental Hospitalization and Imprisonment on Homicide in the United States, 1934 - 2001

This data set explored the effect of imprisonment on violent crime rates prior to 1991. Previous research focused exclusively on rates of imprisonment, rather than using a measure that combines institutionalization in both prisons and mental hospitals. Using state-level panel-data regressions over the 68-year period from 1934 to 2001 and controlling for economic conditions, youth population rates, criminal justice enforcement, and demographic factors, this study found a large, robust, and statistically significant relationship between aggregated institutionalization (in mental hospitals and prisons) and homicide rates. This finding provided strong evidence of what should now be called an institutionalization effect -- rather than an imprisonment or incapacitation effect. Demographic information collected include national unemployment rates and institutional race and age composition.

本数据集探究了自1991年之前监禁对暴力犯罪率的影响。先前的研究仅专注于监禁率，而非采用结合监狱和精神病院两者机构化的综合指标。通过对1934年至2001年长达68年的州级面板数据进行回归分析，并控制经济状况、青年人口比率、刑事司法执法和人口统计学因素，本研究发现，综合机构化（包括精神病院和监狱）与谋杀率之间存在显著、稳健且统计上具有意义的关联。这一发现为所谓的机构化效应提供了强有力的证据——而非监禁或禁锢效应。所收集的统计数据包括国家失业率以及机构的种族和年龄构成。