Similarly, an analysis of a given set of judges all hearing the same criminal cases on the same State supreme courts is likely to reveal substantial differences across individual judges and across demographic types of judges with regard to political party affiliation, prior occupation, ethnic group membership, and liberalism attitudes. This paper presents the results of a series of quantitative social science studies dealing with discretion in the criminal justice system. The studies are concerned with the occurrence of disparities based on the demographic characteristics of defendants and judges; the development of internalized incentives to channel criminal justice discretion along lines that are in conformity with the law; the rational reduction of discretion; and the external controlling of discretion so as to reduce the disparities, rather than the discretion. Tables, graphs, and 32 footnotes are provided.