MODELLING SHOWS VICTORIAN RECIDIVISM RATES SLIGHTLY UNDER 60%

Here’s how the model works. I will do a separate post on the actual numbers.

That means 60% of prisoners wind up back in gaol. So if one of the aims of the prison system is rehabilitation then it is failing miserably.

Prisoners come out of prison into the community. We know that 43.7% of prisoners returned to prison within two years of release having reoffended. 

This actually means that 28% return after one year and 24% return after two years. But, prisoners continue reoffending in subsequent years. Statistically, this means 19%, 15% and 12% reoffend in the next three years. After the numbers are relatively inconsequential.

System Dynamics is very good at modelling this sort of problem. This is what the model looks like. 

Let’s assume that 100 prisoners were released flow into the conveyor on the right-hand side. 

Total released	Year 1	Year 2	Year 3	Year 4	Year 5
100	72	55	45	38	33

Numbers who remain in the community

	Year 1	Year 2	Year 3	Year 4	Year 5
No of Recidivists	18	17	10	7	5

Number re-offending each year

The graph of the recidivist numbers suggests the modelling is conservative. However, this comes with a caution that is probably justified. 

The original 43.7% that the modelling is based on is based on empirical evidence and the modelling is based on statistical projections.

The causes of recidivism are deeply entrenched in the society into which the prisoners are released and are difficult to eradicate. However, with some prisons returning as many as 11 times, recidivism is a profound problem for the Victorian system and without finding some solution the numbers in Victorian prisons will continue to escalate.