Prison Recidivism 2011 and 2012 Cohorts

1. What do Prison Recidivism Statistics measure?

   Recidivism statistics measure the level of recorded reoffending by offenders who received a custodial sentence, following their release from prison. The recidivism rate indicates the percentage of people who were convicted for a crime incident that was recorded within three years of their release.

2. Are these statistics "Under Reservation"?

   These statistics are produced using a combination of Garda Síochána and Irish Prison Service records. All statistics produced by the CSO that utilise the PULSE dataset are classified as Under Reservation. The classification has been applied to reflect the concerns of the CSO as to the completeness and accuracy of PULSE data.

   Further information on the rationale for, and the implications of, the Under Reservation classification may be found here:Under Reservation Explanation

3. How is the Prison Recidivism rate calculated?

   In order to calculate the rate of recidivism it is necessary to match records from data collated by the Irish Prison Service with the Garda PULSE data.

   The matching process results in the selection of a PULSE identifier (or identifiers) for each subject. Convictions data is then examined to determine if individuals who served a prison sentence had any subsequent convictions.

4. How are records matched?

   Due to the absence of a unique identifier in the Irish Criminal Justice system the matching process involves the comparison of individual records. In the region of 60% of all matches are made automatically.

   Due to data quality issues and limitations on the reliability of some information provided to law enforcement authorities, the remaining 40% of matches require manual examination.

   Methodological improvements to the matching process were introduced for the 2011 and 2012 cohorts. These improvements involve the introduction of new software and an updated matching protocol. The improvements have increased the reliability of the matching process but in the absence of a common identifier in the criminal justice system there will always be a degree of subjectivity associated with the matching process.

5. Are the rates of Probation and Prison Recidivism comparable?

   The Probation and Prison publications were developed separately. They were designed primarily to meet the information needs of the Irish Probation Service and the Irish Prison Service. The needs of these organisations are broadly similar but there are some differences. For example, convictions must be secured within 24 months of the date that the crime incident was reported to be included in the calculation of the Probation Recidivism rate. No such requirement exists with respect to the calculation of the Prison Recidivism rate. Certain offences such as traffic offences are not included in the calculation of the rate. The exact list of exclusions differs somewhat between the publications.

    It is also important to bear in mind that the characteristics of the cohorts under consideration differs. The prison cohort tend to have committed more serious offences than their probation counterparts. Due to the differences discussed it is not possible to make direct comparisons.

6. Is it possible to make comparisons across jurisdictions?

   The definitions used in recidivism studies are not standardised internationally. The recidivism window, that is the time period after release from prison during which reoffences are considered, varies across jurisdictions. There are also variations as to what constitutes a reoffence. In some countries a custodial sentence is necessary while other countries consider rearrest to be the most appropriate measure.

   It is extremely difficult to compare Recidivism rates across jurisdictions due to differences in definitions, data quality, legal systems, legal culture and justice policy. Controlling for these differences would be a complex, but essential, process to draw meaningful conclusions from comparisons.

Go to next chapter:Additional Statistical Tables