Find 'em, catch em', put 'em in prison: how to reduce the crime rate

From theory to evidence

This theory has been tested in various countries, including Australia. Most studies find that the probability of detection and punishment does indeed exert a significant influence on rates of criminal behaviour. Reviewing the evidence, Don Weatherburn concludes: "There is now plenty of evidence suggesting that punitive policies do indeed reduce or help constrain the growth in crime. In many instances they provide the only viable short-term option for dealing with it."

Two studies have been carried out in Australia. The first, nearly 20 years ago by Glenn Withers, compared the effects of employment, poverty, education, demographics and even television output with the effect of clear-up rates and imprisonment rates and concluded: "The major reliable determinants of crime rates were found to be committal and imprisonment rates." More recently, Withers' study was repeated by Phillip Bodman and Cameron Maultby using data for the period 1982 to 1991 with a similar result. Robbery, burglary, car theft and fraud all varied significantly with both the number of crimes solved or clear-up rate (a proxy for the probability of getting caught) and the average length of prison sentences (the severity of punishment), although interestingly, the study also found a significant effect for unemployment rates too.

Charles Murray's analysis of the potency of penal policy

In 1997, Charles Murray published an essay in the UK entitled Does Prison Work?. In it, he showed that crimes reported to the police in England and Wales had been rising over several decades at the same time as the probability of being apprehended and incarcerated had been falling. Even though the absolute number of prisoners in Britain had increased as crime went up, the likelihood of being locked up if you committed a serious crime had fallen. As Murray put it: "In 1955, crime began to get safer in England."

Murray contrasted this with what had happened in the United States. Not only has the US a substantially higher imprisonment rate per head of population than other Western countries, but it has also since the late 1970s had a rising rate of imprisonment per recorded crime. Murray believes that the decline in crime rates across the US that began in the 1980s and continued into the 1990s was to a large extent the result of the willingness of the US to increase its use of imprisonment to match the escalation in crime-something the UK failed to do.

Comparing US and UK crime and prison trends, Murray drew two basic lessons:

"Lesson 1: When crime is low and stable, it is a catastrophe to stop locking people up . . . Lesson 2: Prison can stop a rising crime rate and then begin to push it down.'"

Reactions to Murray

Not surprisingly, Murray's argument attracted widespread criticism. Jock Young spoke for many when he charged Murray with overlooking the inherent complexity of crime as a social phenomenon and ignoring sociological, psychological and cultural factors implicated in any analysis of international crime rates.
This is true, but we are still left with the stark statistics on which Murray based his case. Of course, correlations like these do not demonstrate causation - correlations have to be explained. Equally, however, correlations like these cannot simply be ignored.
Referring to American criminologist John DiIulio Murray anticipated many of the criticisms that were levelled against him:

John DiIulio, weary of hearing the critics of prison repeat that 'Incarceration is not the answer,' got to the heart of the matter: 'If incarceration is not the answer,' he asks, 'what, precisely, is the question?'

If the question is: 'How can we restore the fabric of family life and socialize a new generation of young males to civilized behaviour?' then prison is not the answer. If the question is, 'How can we make unemployable youths employable?' prison is not the answer. If the question is 'How can we rehabilitate habitual criminals so that they become law-abiding citizens?' prison is only rarely the answer.
But, if the question is 'How can we deter people from committing crimes?' then prison is an indispensable part of the answer."

Trends in Australia and New Zealand

Does Murray's analysis hold for Australia and New Zealand?
In Australia and New Zealand, as in the US and the UK, the prison population has grown in absolute numbers over the last 40 years, although the growth has been nothing like as large as in the US. Imprisonment per head of population roughly doubled in Australia and New Zealand (and in England and Wales) in the 40 years after 1960, with most of the increase coming after the mid-1980s, although the Australian trend has lagged somewhat behind that of the other two countries.

Where Australia, New Zealand and England and Wales all differ from the US, however, is in the rate of imprisonment per crime committed. That rate fell in all three countries until the mid-1980s. Since then it has remained relatively constant, rising slightly in England and Wales and New Zealand in the last few years while staying flat in Australia. Thus, although the number of prisoners increased in all three countries over the past 40 years, the probability of ending up in prison for a serious offence declined quite dramatically.

Australian penal policies

During the period examined, the guiding principle in Australia has been that imprisonment should only be used as a last resort. Throughout the 1970s and into the 1980s Australia actually decreased its imprisonment rate per head of population despite an escalating crime rate. In a book published in the 1980s, David Biles pointed to the deliberate attempt to reduce imprisonment rates "to the lowest levels that are consistent with public acceptance".
The principle of prison as a last resort remains in evidence in sentencing today, and there are ongoing attempts to lower imprisonment rates in Queensland and in Western Australia.