Those currently in Australian prisons are there for one of two reasons: they have either been remanded in custody pending trial or are serving a custodial sentence after having been convicted by a court. Recent research indicates Australia continues to send more people to prison even though crime rates are falling.

Punishment, or the threat of punishment, alone will not prevent crime. As this report argues, policing strategies, together with changes in economic and social factors, are likely to have played a significant part in the decline of crime rates. Even so, the absolute effect of prison entails that when willingness to use prison as punishment weakens, crime rates can be expected to rise. A question therefore arises as to whether there is a close correlation between rates of imprisonment and rates of crime. One factor to consider is the marginal effect of prison — that is, whether for each additional person sent to prison, there is a corresponding reduction in the rate of crime.

This report investigates the place and purpose of prison in contemporary Australian society and assess the part it plays in the criminal justice systems. It also argues, in line with recent research, that the marginal effect of prison in Australia appears to be declining. But does this account for rising rates of incarceration? First, however, it is important to consider the principal purposes of prison. The report then proceeds to evaluate the merits and problems of prison within the context of the broader criminal justice systems.