The Effect of Differentiation on Prison Population : A Simulation Study of the Swedish Prison System

This paper describes the case of a simulation study of the Swedish Prison and Probation system regarded as a queuing system. The situation in Swedish prisons today is not acceptable with a utilisation over 100 per cent. The short-term solution of the problem has been to overcrowd the prisons. The purpose of this work is to describe the relations between waiting time in remand prison, the official number of cells in prisons and the degree of differentiation regarding to the expected torrent of criminals. Differentiation is the attempt to keep different categories of clients apart during their prison time. The degree of differentiation is defined as the number of defined categories used for client placement. The conclusions from this study is that there are not enough number of prison cell available. The situation for male inmates/clients is more critical than for female clients. The results from the study suggest that there needs to be approximately 11,000 prison cells in total to meet the unofficial recommendation of a maximum of seven days in remand prison.