Document Type


Publication Title

Journal of Criminal & Criminology



Publication Date



prison population; prisoners


A growing empirical literature has sought to explain the forces behind the significant expansion of the U.S. prison population over the past thirty years. Unfortunately, the studies to date have suffered from important methodological, conceptual, and definitional problems that have significantly curtailed their ability to identify causal effects. In this Article, I examine several of the central limitations and discuss remedies. I start by reviewing the theories that investigators have sought to test. I then discuss the studies' empirical defects, such as failing to account for endogenous relationships, overlooking the risk of model dependency, ignoring complex dynamic relationships, using variables that either do not correctly measure the relevant theory or do not isolate it from competing claims, and relying consistently on the same source of data. I also propose several remedies to these and other shortcomings. The current literature has begun to shed light on the forces driving prison growth, but more carefully designed models are needed before we can be confident in the findings.