IMPRISONMENT IS THE FINAL STAGE OF THE ELABORATE CRIMINAL JUSTICE PROCESS THAT FILTERS OUT THOSE FEW PERSONS WHO SHOULD BE GIVEN THIS PENULTIMATE PENALTY. PRINCIPAL UTILITARIAN OBJECTIVES FOR IMPOSITION OF IMPRISONMENT ARE REHABILITATION, DETERRENCE, AND INCAPACITATION. THESE COMPONENT ASPECTS RELATE TO THE CRIME CONTROL EFFECTIVENESS ASSOCIATED WITH IMPRISONMENT. ANY CRIME CONTROL POLICY INHERENTLY INVOLVES A TRADE OFF BETWEEN THE CRIME CONTROL EFFECTIVENESS AND THE SOCIAL COSTS OF IMPLEMENTING IT. THUS, THE EFFECTS MUST BE WEIGHED CAREFULLY AGAINST SOCIAL COSTS ASSOCIATED WITH INCREASING USE OF IMPRISONMENT. ONE MAY VIEW THE PRISON POPULATION AS THE OUTCOME OF A SOCIAL CALCULUS THAT WEIGHS CONFLICTING SOCIAL COSTS. THE CONSTANT U.S. IMPRISONMENT RATE HAS BEEN MAINTAINED IN THE FACE OF THE TRIPLING OF REPORTED INDEX CRIMES AND INCREASED ARREST RATES. TO RATIONALIZE THE ALLOCATION OF THE IMPRISONMENT SANCTION, A STATISTICAL MODEL RELATING THE EFFECTS OF ALTERNATIVE POLICIES ON CRIME AND IMPRISONMENT RATES IS DEVELOPED. CONSIDERATION OF STATISTICAL INMATE AND CRIME RATE DATA SUGGEST THAT USE OF IMPRISONMENT IS FAR LESS FLEXIBLE THAN IT COULD BE. IT IS MORE APPROPRIATE TO CONSIDER IMPRISONMENT POLICY IN TERMS OF ALLOCATION OF A FIXED RESOURCE RATHER THAN IN TERMS OF ADJUSTING THE PRISON POPULATION AND RESOURCE LEVELS. THE RATIONALIZATION PROCESS SHOULD FOCUS ON HOW LIMITED PRISON CAPACITY CAN BEST BE ALLOCATED TO THOSE OFFENDERS WHO REPRESENT THE MOST SERIOUS THREAT TO SOCIETY, BOTH CURRENTLY AND POTENTIALLY. IMPRISONMENT SHOULD BE RESERVED FOR THOSE OFFENDERS WHO COMMIT THE MOST SERIOUS CRIMES AT THE HIGHEST RATE. COMMUNITY-BASED PROGRAMS SHOULD BE USED MORE EXTENSIVELY FOR THOSE POTENTIAL FOR REHABILITATION AND SUCCESSFUL FUNCTIONING IN THE COMMUNITY. IN ADDITION, STATE SENTENCING POLICY COMMISSIONS SHOULD BE USED TO REGULATE SENTENCING POLICY EFFICIENTLY. NOTES, GRAPHS, AND STATISTICAL FORMULAS ARE INCLUDED IN THE CHAPTER. (LWM)