The Direct and Indirect Effects of Socio-Economic Variables on State Imprisonment Rates

Abstract

Almost two decades of research on the exact relationship between socio-economic variables and the rate of incarceration has produced highly divergent results. Some of these inconsistencies may be due to the various models specified (some use total crime rather than violent, and some control for system level variables while others do not). Virtually all of the previous research has focused on the direct effect only. Utilizing 1990 cross-sectional state level data this study examines the direct and indirect effects of socio-economic variables on imprisonment rates while controlling for arrests or crimes rates and system level variables (e.g., prison admissions and releases). Models using arrest rate data rather than crime rates were included to capture the effect of the recent "war on drugs" on imprisonment which is not included in the Index Crime rate data. These data reveal that percent nonwhite has a significant and direct effect on imprisonment levels across the U.S., but less of a direct effect in nonsouthern states. The data also document that percent nonwhite has a substantial indirect effect. The indirect effect of economic inequality is greater than the direct effect. Finally, there was no variation in the effects of extra-legal variables between those models which controlled for system level data and those which did not.