How much crime does prison stop?

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Release Date: Friday 10 February 2006, 10.30am

Prison is more effective in preventing crime than many people think, according to a new study by the NSW Bureau of Crime Statistics and Research.

The Bureau estimates that the current imprisonment rate for convicted burglars prevents about 45,000 burglaries per year.

However according to the Bureau using prison to further reduce the burglary rate would be both expensive and fraught with difficulty.

Doubling the average sentence length for burglary (from one to two years) in New South Wales (NSW) would reduce the annual number of burglaries in NSW by eight percentage points or about 10,000 offences,

Doubling the percentage of convicted burglars who get a prison sentence (from 44 per cent to 88 per cent) or the clear up rate (from six to 12 per cent) could reduce the annual number of burglaries by up to 11 percentage points or about 14,000 offences.

To get a 10 per cent reduction in burglary, however, the number of convicted burglars held in prison at any one time would have to be increased by about 34 per cent. This would cost more than $26 million per annum. If the introduction of tougher penalties were to result in less 'criminally productive' burglars being put in prison the true cost would be even higher than this.

The Bureau also warns that relying on tougher prison penalties to reduce burglary will backfire if either (a) tougher penalties cause an increase in the percentage of defendants who plead 'not guilty' and end up acquitted or (b) higher rates of imprisonment lead over the long-term to higher rates of joblessness among offenders.

Commenting on the findings, the director of the Bureau, Dr Don Weatherburn, said they leave little doubt that prison is an important tool in the fight against certain kinds of crime.

"What remains unclear is whether further investment in prison is the most cost-effective way of getting the crime rate down. There are other effective but less expensive ways of reducing crime (e.g. coerced treatment, post-release support for ex prisoners) that may give more value for the taxpayer's dollar", he said.

Further enquiries: Dr Don Weatherburn 9231-9190 or 0419-494-408