Interjurisdictional differences in Australian imprisonment rates: Sentencing or arrest rates?
There are stark and enduring differences between the Australian States and Territories in their rates of imprisonment.
After 20 years of falling crime rates (Weatherburn & Rahman, 2021), Australia now finds itself in the invidious position of having incarcerated a larger share of its adult population than at any point since the late 19th century (Leigh, 2020). Those unfamiliar with the evidence might think that the fall in crime is due to rising imprisonment rates, but that would be a mistake. Two rigorous studies of the effect of imprisonment on crime in Australia have been conducted over the last few years. The first, by Wan et al. (2012) concluded that a 10% increase in the likelihood of prison would reduce property crime by 1.2% and violent crime by 1.7%. The second, by Bun et al. (2020), concluded that a 10% increase in the risk of a prison sentence would reduce property crime by 0.02% and violent crime by 0.03%. Neither study found any significant effect of increasing sentence length. If the Wan et al. (2012) study is accepted, less than 6% of the decline in crime in Australia between 2001 and 2020 is due to the rise in imprisonment risk. If the Bun et al. (2020) study is accepted the contribution of prison is less than 1%.
Read the paper here in The Journal of Criminology.