Prison overcrowding can be prevented or relieved through the appropriate management of official decisions affecting prison admissions, accelerated release, and parole. If such decisions are to be uniformly effective in managing prison populations and in handling similar offenders equitably, guidelines must structure these decisions. Guidelines are based on an empirical analysis of existing decisionmaking factors and patterns, an assessment of the extent to which existing decisionmaking complies with the values desired, and the construction and ongoing revision of guidelines to produce decisions that serve policy goals. This procedure refutes critics of guidelines who charge that they encase the flawed decisionmaking of the past in an unchangeable structure. Guidelines constructed by the procedure previously described have been shown through empirical testing to reduce sentencing inequity and to promote accountability. Guidelines have also aided in controlling prison crowding. A 1982 study of the impact of Minnesota's sentencing guidelines indicates that in the initial period of their implementation, prison populations remained within the State correctional capacity, and admissions approximated the projected levels. Guidelines for bail have had a similar effect on jail admissions. A number of States have adopted guidelines for emergency release decisions to relieve overcrowded facilities. Parole guidelines have also been developed in many States. Overall, guidelines produce equitable decisions structured to maintain an acceptable level for prison and jail populations. 93 footnotes.