The effect of available capacity on jail incarceration: An empirical test of Parkinson's law

Abstract

The strong positive association between available capacity and incarceration rates has been interpreted by social scientists as consistent with one of two competing hypotheses: (1) that available capacity affects rates of incarceration or (2) that capacity levels respond to variations in confinement populations. Although these two alternative hypotheses imply different causal mechanisms, it has been difficult to adjudicate between them, in part because of the data and methodologies employed in prior research. This study investigates whether a large increase in jail capacity in Orange County, Florida increased daily jail incarceration levels above that expected on the basis of preexisting incarceration trends and police activity. Results are consistent with the hypothesis that available capacity influences incarceration levels. The number of daily arrests made by police, however, is of little consequence in predicting levels of jail incarceration. Taken in total, these findings suggest that adding additional capacity may act to accelerate the growth of confinement populations.