Review of the Prison Overcrowding and Double-Bunking Literature

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Key Words

Crowding, double-bunking, accommodation strategies

What it means

The literature suggests there is not a strong relationship between institutional misconduct and crowding, but it does suggest that strategies are available to mitigate effects. Ensuring staffing ratios and availability of program options are examples of mitigation strategies. While double-bunking is a method of addressing crowding, it needs to include appropriate selection methods for shared accomodations.

Why we did this study

Prison population pressures are being experienced in a number of countries, including Canada. Between March 2010 and March 2012 the federal inmate population in Canada increased by approximately 900 or 6.3 per cent. It has been argued that increases could affect the safety and security of the offenders and staff. As such it is important to identify if and what effects institutional crowding may have and what mitigation strategies can be implemented.

What we did

A review of the literature was conducted to identify what effects crowding has on the offenders and staff and what challenges Correctional Service of Canada (CSC) may have to address. Additionally, CSC's current strategies to mitigate possible negative effects as well as strategies used by other correctional organizations were reviewed.

One of the commonly used strategies by all countries reviewed, double-bunking, was investigated further. A review of procedures for matching offenders to share cells, as this is expected to assist in the successul practice of double-bunking, was also completed.

What we found

Most of the research focuses on the relationship between crowding and institutional misconduct. While results vary with methodologies, overall results aggregated across studies suggests there is a small effect of crowding on institutional misconduct. In addition, there have been studies suggesting crowding affects the level of stress experienced by the offender and reduces the availability of programming, thus it is important that effective strategies are implemented to mitigate any negative impacts that may occur due to institutional crowding.

CSC shares several strategies with the correctional organizations of other countries. One commonly used strategy to deal with crowding is double-bunking; therefore, the impact double-bunking could have on the offender population was also reviewed. There is limited research on this topic, however the studies that do exist point to higher illness complaints and higher rates of non-aggressive infractions. Research has also demonstrated that double-bunking can be implemented without an increase in risk to offenders or staff if appropriate procedures are in place. One promising technique is conducting a cell sharing assessment with each offender. This essentially uses structured guidelines to identify vulnerabilities and risk factors, among other characteristics, to determine eligibility and potential double-bunking success.

For more information

Paquin-Marseille, L., Grant, B. A., & Michel, S. (2012). Review of the Prison Crowding and Double-Bunking Literature. Research Report, R-266. Ottawa, ON: Correctional Service of Canada.

To obtain a PDF version of the full report, contact the following address:

Prepared by: Steven Michel


Research Branch

(613) 996-3287