Date of Conferral





Public Policy and Administration


Matthew Jones


Although a widely used practice, it was previously unknown whether disciplinary segregation is actually effective at modifying prison behavior. This quantitative, retrospective observational study tested deterrence theory and explored the effectiveness of disciplinary segregation in deterring subsequent prison inmate misconduct among those subjected to it (N = 228). It compared a cohort of male inmates incarcerated by the Oregon Department of Corrections who had spent time in disciplinary segregation in 2011 and/or 2012 with a comparison cohort who had not spent any time in disciplinary segregation. Three models were tested, each with the outcome variable operationalized in a different way: overall total rule violations in 2013-2014, total major rule violations in 2013-2014, and total minor rule violations in 2013-2014. Multiple regression analysis was used to control for the influence of age, time spent on current sentence, risk score, prior major and minor rule violations, and time spent in disciplinary segregation. These analyses revealed that for each model, disciplinary segregation was not a significant predictor of subsequent prison inmate misconduct. The findings suggest that deterrence theory does not explain the relation between the experience of disciplinary segregation and subsequent prison misconduct among those subjected to it. The findings further suggest that disciplinary segregation neither decreases nor increases subsequent prison misconduct. These results indicate that disciplinary segregation should undergo a critical evaluation by prison administrators, which could lead to the practice of disciplinary segregation being exercised in a more judicious and informed manner, thus limiting its potentially negative effects and contributing to positive social change.