USING ROUTINE STATISTICS IN ESTIMATING PRISON POPULATION FOR POLICY ASSESSMENT

In order to assess adequately the consequences of justice system plann ing, it is necessary to have a clear understanding of the effects that resulting policies may have on prison population. Unfortunately, it i s often the case that the basic arithmetic involved in assessing such effects does not appear to be well understood. This paper discusses a ''stock and flow'' model that utilizes a simple arithemic formula that can be applied to assess practical problems that involve population f lows. Examples are introduced that demonstrate possible applications o f this model for assessing population effects relative to sentencing p olicy. The model will be of particular interest to policymakers, membe rs of the judiciary, and corrections administrators.