Research Summary:Several prominent empirical studies estimate models of a constant proportional effect of prison on crime, finding that effect is substantial and negative. A separate literature argues against the crime-reducing effect of prison but mainly on theoretical grounds. This second literature suggests that the elasticity of the prison/crime relationship is not constant. We provide a model that nests these two literatures. Using data from the United States over 30 years, we find strong evidence that the negative relationship between prison and crime becomes less strongly negative as the scale of imprisonment increases. This revisionist model indicates that (1) at low levels of incarceration, a constant elasticity model underestimates the negative relationship between incarceration and crime, and (2) at higher levels of incarceration, the constant elasticity model overstates the negative effect. Policy Implications:These results go beyond the claim of declining marginal returns, instead finding accelerating declining marginal returns. As the prison population continues to increase, albeit at a slower rate, after three decades of phenomenal growth, these findings provide an important caution that for many jurisdictions, the point of accelerating declining Over the last 25 years, the population behind bars has grown at an astounding rate. From 200,000 inmates in 1973, the federal and state inmate population surpassed the one million mark in 1994, with more recent growth bringing the total to 1.4 million. Through much of this buildup period, researchers have disagreed over the effectiveness of the buildup in reducing the crime rate.

A substantial build-up in prison capacity and the use of incarceration in the USA began in the mid-1970s and continued through to the end of the century. Researchers generally agree that a broad-based social movement supported the build-up, but disagree over the core features of the movement. Some researchers argue that it was the by-product of social discontents associated with rapid social change. Other researchers contend that the movement was an instance of purposeful people seeking solutions to a problem. Across several data sets, little evidence is found to support the position that advocates of the prison build-up had suffered from recent social changes. Instead, the evidence suggests that people supported the build-up for instrumental reasons.

Different elements of local police agencies’ terrorism preparedness may be associated with different organizational/environmental variables. We use 2003-2007 data (showing considerable adoption and desistance of practices) on medium-to-large-sized local agencies to examine relationships between contingency (vulnerability, organizational characteristics) and contagion (network/isomorphic influence) measures and preparedness elements, including terrorism special units, dedicated assignment of personnel, terrorism-related community outreach, computerized intelligence files, and interagency-shared radio frequencies. Modeling 2007 preparedness revealed consistencies and some differences in the associations between these measures and the different preparedness elements. The finding of no association between objective vulnerability score and any terrorism preparedness action particularly warrants further research attention. It will also be important to extend preparedness research into the recent period of economic recession.

Research Summary:Several prominent empirical studies estimate models of a constant proportional effect of prison on crime, finding that effect is substantial and negative. A separate literature argues against the crime-reducing effect of prison but mainly on theoretical grounds. This second literature suggests that the elasticity of the prison/crime relationship is not constant. We provide a model that nests these two literatures. Using data from the United States over 30 years, we find strong evidence that the negative relationship between prison and crime becomes less strongly negative as the scale of imprisonment increases. This revisionist model indicates that (1) at low levels of incarceration, a constant elasticity model underestimates the negative relationship between incarceration and crime, and (2) at higher levels of incarceration, the constant elasticity model overstates the negative effect. Policy Implications:These results go beyond the claim of declining marginal returns, instead finding accelerating declining marginal returns. As the prison population continues to increase, albeit at a slower rate, after three decades of phenomenal growth, these findings provide an important caution that for many jurisdictions, the point of accelerating declining Over the last 25 years, the population behind bars has grown at an astounding rate. From 200,000 inmates in 1973, the federal and state inmate population surpassed the one million mark in 1994, with more recent growth bringing the total to 1.4 million. Through much of this buildup period, researchers have disagreed over the effectiveness of the buildup in reducing the crime rate.