Australia could free a third of its prisoners with little risk to community, new research finds

The research paper by Prof Mirko Bagaric, the dean of law at the Swinburne University of Technology, recommends law reform to prevent imprisonment of non-violent offenders.

Bagaric noted that 42% of prisoners have not committed a violent or sexual offence. He calculated a reduction in the prison population of about one-third would be possible even if the 10% of offenders who have committed serious property crime or serious drug offences remained in prison.

In October Leigh told the Australian Institute of Criminology that taxpayers are each forking out $140 more a year for prisons than would be needed if Australia maintained its 1985 rates of incarceration.

In Australian states, which are responsible for most criminal law, both major parties typically make a virtue of tougher sentencing.

The US has recently experienced declines in the prison population, with some of the biggest declines in liberal states in the north-east.