Incarceration

The Australian Bureau of Statistics paper An analysis of repeat imprisonment trends in Australia using prisoner census data from 1994 to 2007, Aug 2010 [PDF] suggests that reincarceration in Australia is strongly associated with being young, being Indigenous, or having been previously imprisoned (that is, being a prisoner who had already served time in prison). The rate of reincarceration in all jurisdictions except Queensland in recent years was higher than in the mid-1990s. The paper builds on ABS research such as that noted here last year.

The 64 page paper by Jessica Zhang & Andrew Webster comments that -

Reducing the number of prisoners who are repeatedly imprisoned is one of the goals of any correctional system. However, while a period of imprisonment may deter some people from re-offending, in others it may foster further criminal behaviour. This paper presents the results of a study based on a longitudinal dataset constructed from 14 successive Prisoner Censuses between 1994 and 2007 to follow, over time, two cohorts of people who were 'released' from prison (where 'release' is a proxy measure derived from the absence of a prisoner's record in a subsequent Prisoner Census). This paper expands on an earlier study by the Australian Bureau of Statistics by using logistic regression models to examine the factors associated with repeat imprisonment and assess whether or not the propensity for reimprisonment has increased over time. This paper also examines trends in criminal career development using descriptive methods, looking at patterns of specialisation, and of movements from one type of offence to another.

The authors explain that -

Since 1994 the Australian Bureau of Statistics has collected data, including the National Prisoner Census, from administrative data sources maintained by corrective services agencies in each state and territory. The annual National Prisoner Census provides a snapshot of the prisoner population at 30 June each year. The Census data provides information on certain demographic and sentencing characteristics of the prisoners including age, sex, Indigenous status, most serious offence, and an indicator of prior imprisonment episodes.

To follow the prisoners over time, a longitudinal dataset on the prisoner population was constructed by linking the annual datasets. The longitudinal dataset constitutes a series of snapshots rather than a complete picture of prisoner inflows and outflows over time, however analysis of the dataset provides unique insights into
reimprisonment trends.

Because the Prisoner Census does not collect information on the release of prisoners, this paper uses people’s disappearance from the Prisoner Census between successive years as a proxy for their release from prison, and their reappearance in the census as a proxy for their reimprisonment. In this paper, the term 'release' is therefore used to refer to 'disappearance' from the Prisoner Census. The two limitations associated with this indirect measurement of release from prison are:

1) that there is no precise date for release available; and
2) that imprisonment episodes of less than one year would be missed if they did not span 30 June.

Despite the limitations, the 14 year longitudinal dataset (1994–2007) is a valuable source of information for exploring the characteristics of prisoners with multiple imprisonment episodes, especially those imprisoned for a year or more.

This study uses the longitudinal Prisoner Census dataset to investigate two broad topics:

= Factors associated with reimprisonment and whether the rate of reimprisonment has changed over time, and
= Trends in the criminal career paths of prisoners with multiple prison episodes.

These topics are explored by primarily studying the cohort of 28,600 prisoners who were ‘released’ during the period July 1994 to June 1997. This release cohort were followed from their release until June 2007, a span of at least ten years. To investigate whether the rate of reimprisonment has changed over time, the reimprisonment rate for the 1994–1997 release cohort three years after release is compared with a second release cohort of 26,700 people released from prison in 2001–2004.

Findings by Zhang & Webster include the observations that -

= nearly 60% of prisoners released during the period July 1994 to June 1997 had not been reimprisoned by 30 June 2007.

= Rates of reimprisonment and specialisation (a high rate of reimprisonment for the
same offence) differed considerably by original offence type

= There was a high degree of specialisation in illicit drug offences, sexual assault and road traffic offences. However, prisoners who were originally imprisoned for committing offence types other than illicit drug offences, sexual assault and road traffic offences did not tend to move into these offence types.

= There was also a high level of specialisation in acts causing injury, robbery, burglary and theft. A high proportion of prisoners also moved into these offence types for their second and subsequent prison episodes. Therefore, irrespective of their original offence, many repeat prisoners were reimprisoned for committing these offences.

= Many offenders were reimprisoned for offences against justice (eg breaking parole) at some stage. This may be attributed to breaches of justice orders.