Effects of custodial vs . non-custodial sentences on re-offending September

Reviewer: Martin Killias and Patrice Villettaz, School of Forensic Science and Criminology, University of Lausanne, CH-1015 Lausanne, Switzerland. E-mail: Martin.Killias@ipsc.unil.ch. Phone: (0041-21) 692 46 40, Fax (0041-21) 692 46 05 Objective: To assess the relative effects of imprisonment and non custodial ("alternative" or "community") sanctions on reoffending. Background: Throughout the western world, community-based sanctions have become a popular and widely used alternative to custodial sentences. There have been many comparisons of rates of reconviction among former prisoners and those who have served any kind of community sanction. So far, the comparative effects on reoffending of custodial and non custodial sanctions is unresolved, due to many uncontrolled variables. Search Strategy: Relevant studies which meet the eligibility criteria (see below) will be identified through multiple sources, including abstracts, bibliographies, and contacts with experts in all possible countries. Eligibility Criteria: Randomized or quasi-randomized experiments, as well as non exp erimental comparisons between former prison inmates and those who served community sanctions will be included, provided that variables in addition to those found in registers have been controlled for (attitudes, personal or employment history etc.). Studies published in any language after 1960 will be considered for inclusion. Data Collection and Analysis: A coding protocol will be prepared along the guidelines of the Campbell Collaboration. Sources of Support: An application for funding of this review has been filed at the National Science Foundation of Switzerland. The decision is expected to arrive by March, 2003. Financial support by the National Science Foundation of Switzerland does not affect the independence of the reviewers. Background In the late 19 century, leading criminal law teachers (such as Franz von Listz in Germany, Adolphe Prinse in Belgium, Bonneville de Marsangy in France, and van Hamel in the Netherlands) promoted the idea that short-term imprisonment is damaging, since inmates are in custody for too short a period to allow any treatment to be effective, and for too long to avoid contamination with more severe criminal propensities through the contacts with other prisoners. The basis for this theory was the idea that crime is like a disease which, if not thoroughly treated, will worsen and, ultimately, contaminate others (for a review of the origins of this theory, see Killias 2002, 2001). This led to the call for the substitution of short-term imprisonment by either long sentences, or by "alternative" sanctions such as fines, suspended sentences, or probation (Franz von Listz, 1882). Later, more "modern" alternatives were "invented", such as community service or electronic monitoring. Over the decades and throughout the western world, community-based sanctions have become a popular and widely used alternative to custodial sentences. There have been many comparisons of rates of reconviction among former prisoners and those who have served any kind of community sanction. So far, the comparability of these rates is questionable due to many uncontrolled variables. Eligibility Criteria There are probably several thousand studies across western countries in which reoffending (mostly reconvictions) has been compared between former prisoners and those who served any type of "alternative" or non custodial sentence. On the scale developed by Sherman et al. (1997), many studies of this kind would be classified at level 3. Usually, the controls were limited to the variables available in official files, such as number and type of previous convictions, sex and age. However, offenders who receive different types of sanctions tend to differ in many other ways which are likely to be related to risks of reoffending, such as attitudes, employment record, drug or alcohol abuse history, etc. Therefore, for this reason, any conclusions about "superiority" (in terms of special deterrence) of "alternative" over custodial sanction are questionable. Since the bias is systematic in all studies of this kind, including them and computing any mean effects would, at best, be misleading. Given the huge number of studies of this kind, including all of them would also considerably increase the investment in time and funds without any significant benefits. In order to produce a review within acceptable time limits and with feasible resources, only studies that meet the higher methodological standards will be included in the review. However, we shall establish a list of all identifiable studies which compared reoffending after imprisonment and any alternative sanction. On the basis of such an inventory, our decisions concerning eligibility should be transparent. It will also be possible to extend the review to studies of lower methodological standards in a later stage. The inventory will allow us to make an estimate of the required investment in time and human ressources. Types of studies (1) Randomized experiments where reoffending rates among former prisoners and those who served any form of community-based sanction have been compared ; (2) Quasi-experimental comparisons, for exemple, those based on studies where groups of convicts who were eligible for an "alternative" sanction as part of an amnesty package were compared with others who were not (and who had served their time in prison). In studies of this kind, the criterion for eligibility for an "alternative" sanction was usually a certain date at which the offence had occurred (and which coincided with a significant royal or strate event in the country). In such cases, eligibility for an "alternative" sanction was presumably independent of offender characteristics ; (3) Quasi-experimental studies where the comparison included variables which went beyond information which is routinely found in criminal registers (such as prior convictions). In particular, studies using (interview) data on employment or drug/alcohol abuse history, or on attitudes, will qualify for inclusion. Types of sanctions All studies meeting these criteria where "alternative" or community-based sanctions have been compared with custodial sanctions will be considered. To qualify for the review, a study would, however, need to have compared imprisonment with any of these "alternative" sanctions; comparisons between several community sanctions (e.g. community work vs. electronic monitoring) will not be included. Studies will be considered for inclusion regardless of the length of custodial sentences. Some studies have indeed compared prisoners who, after a considerable time in custody, have been paroled (and transferred to a program of electronic monitoring), and those who had to serve their entire sentence. Only sanctions (as part of a formal sentence) will be considered. Thus, studies on police cautioning will not be included, since this is not a judicial sentence, nor will be studies on "alternatives" to pretrial detention. Studies comparing immediate detention before any judicial hearing (such as in cases of domestic violence in the United States and many other countries) will not be included. Types of outcome measures Most studies concentrate on reconviction. This is certainly a key variable, but efforts will be made to find more differentiated indicators of reoffending. For example, some studies have shown that the frequency of new convictions is far lower after any type of intervention (compared with a pre-conviction period of same length), and that arrest data may differentiate better between groups of offenders who were treated in different ways. This may be particularly true in countries where re-incarceration (for parole violations) is more common than reconviction for a new offence. Some studies have also used self-report data in order to assess the outcome of different interventions. In smaller experiments, the experimental and the control group may differ in outcome because they differed from the beginning. We shall, therefore, give priority to relative improvement rather than to absolute levels. In order to assess improvement, we shall look not only at prevalence of reconvictions (or percentage of those who re-offend), but also at "incidence" rates (or rates of new offences per unit time). Relative improvement can be computed as the standardized mean difference. Search Strategy Relevant studies which meet the eligibility criteria will be identified through multiple sources, including abstracts, bibliographies (in any language), databases (such as those listed under the Campbell Crime and Justice Group website, as well as the National Criminal Justice Reference Service NCJRS and C2-SPECTR that includes more than 10,000 citations of randomised and possibly randomised studies), and contacts with experts in all possible countries. The staff of the School of Forensic Science and Criminology of Lausanne University is multi-lingual. It includes researchers fluent in English, French, German, Italian, Spanish, Dutch, Serbo-Croatian, and Russian. This should allow coverage of all but a few studies without the need for external translators. Through international channels, such as the European Sourcebook of Crime and Criminal Justice Statistics (with its network of correspondents in 40 countries), the European Society of Criminology and the International Society of Criminology, contacts could be established with countries not routinely covered in international reviews of research. This may be helpful since some research might have been conducted outside the English-speaking world. Given that some very relevant quasi-experimental studies were published during the 1960s, we propose to include studies from 1960 onwards on the assumption that not many older studies would be relevant for this review. In case the number of level-3 studies is overwhelming, we may apply a more recent time limit (e.g. 1990) in establishing an inventor


Background
In the late 19 th century, leading criminal law teachers (such as Franz von Listz in Germany, Adolphe Prinse in Belgium, Bonneville de Marsangy in France, and van Hamel in the Netherlands) promoted the idea that short-term imprisonment is damaging, since inmates are in custody for too short a period to allow any treatment to be effective, and for too long to avoid contamination with more severe criminal propensities through the contacts with other prisoners. The basis for this theory was the idea that crime is like a disease which, if not thoroughly treated, will worsen and, ultimately, contaminate others (for a review of the origins of this theory, see Killias 2002Killias , 2001. This led to the call for the substitution of short-term imprisonment by either long sentences, or by "alternative" sanctions such as fines, suspended sentences, or probation (Franz von Listz, 1882). Later, more "modern" alternatives were "invented", such as community service or electronic monitoring.
Over the decades and throughout the western world, community-based sanctions have become a popular and widely used alternative to custodial sentences. There have been many comparisons of rates of reconviction among former prisoners and those who have served any kind of community sanction. So far, the comparability of these rates is questionable due to many uncontrolled variables.

Eligibility Criteria
There are probably several thousand studies across western countries in which reoffending (mostly reconvictions) has been compared between former prisoners and those who served any type of "alternative" or non custodial sentence. On the scale developed by Sherman et al. (1997), many studies of this kind would be classified at level 3. Usually, the controls were limited to the variables available in official files, such as number and type of previous convictions, sex and age. However, offenders who receive different types of sanctions tend to differ in many other ways which are likely to be related to risks of reoffending, such as attitudes, employment record, drug or alcohol abuse history, etc. Therefore, for this reason, any conclusions about "superiority" (in terms of special deterrence) of "alternative" over custodial sanction are questionable. Since the bias is systematic in all studies of this kind, including them and computing any mean effects would, at best, be misleading. Given the huge number of studies of this kind, including all of them would also considerably increase the investment in time and funds without any significant benefits.
In order to produce a review within acceptable time limits and with feasible resources, only studies that meet the higher methodological standards will be included in the review. However, we shall establish a list of all identifiable studies which compared reoffending after imprisonment and any alternative sanction.
On the basis of such an inventory, our decisions concerning eligibility should be transparent. It will also be possible to extend the review to studies of lower methodological standards in a later stage. The inventory will allow us to make an estimate of the required investment in time and human ressources.

Types of studies
(1) Randomized experiments where reoffending rates among former prisoners and those who served any form of community-based sanction have been compared ; (2) Quasi-experimental comparisons, for exemple, those based on studies where groups of convicts who were eligible for an "alternative" sanction as part of an amnesty package were compared with others who were not (and who had served their time in prison). In studies of this kind, the criterion for eligibility for an "alternative" sanction was usually a certain date at which the offence had occurred (and which coincided with a significant royal or strate event in the country). In such cases, eligibility for an "alternative" sanction was presumably independent of offender characteristics ; (3) Quasi-experimental studies where the comparison included variables which went beyond information which is routinely found in criminal registers (such as prior convictions). In particular, studies using (interview) data on employment or drug/alcohol abuse history, or on attitudes, will qualify for inclusion.

Types of sanctions
All studies meeting these criteria where "alternative" or community-based sanctions have been compared with custodial sanctions will be considered. To qualify for the review, a study would, however, need to have compared imprisonment with any of these "alternative" sanctions; comparisons between several community sanctions (e.g. community work vs. electronic monitoring) will not be included.
Studies will be considered for inclusion regardless of the length of custodial sentences. Some studies have indeed compared prisoners who, after a considerable time in custody, have been paroled (and transferred to a program of electronic monitoring), and those who had to serve their entire sentence.
Only sanctions (as part of a formal sentence) will be considered. Thus, studies on police cautioning will not be included, since this is not a judicial sentence, nor will be studies on "alternatives" to pretrial detention. Studies comparing immediate detention before any judicial hearing (such as in cases of domestic violence in the United States and many other countries) will not be included.

Types of outcome measures
Most studies concentrate on reconviction. This is certainly a key variable, but efforts will be made to find more differentiated indicators of reoffending. For example, some studies have shown that the frequency of new convictions is far lower after any type of intervention (compared with a pre-conviction period of same length), and that arrest data may differentiate better between groups of offenders who were treated in different ways. This may be particularly true in countries where re-incarceration (for parole violations) is more common than reconviction for a new offence. Some studies have also used self-report data in order to assess the outcome of different interventions.
In smaller experiments, the experimental and the control group may differ in outcome because they differed from the beginning. We shall, therefore, give priority to relative improvement rather than to absolute levels.
In order to assess improvement, we shall look not only at prevalence of reconvictions (or percentage of those who re-offend), but also at "incidence" rates (or rates of new offences per unit time). Relative improvement can be computed as the standardized mean difference.

Search Strategy
Relevant studies which meet the eligibility criteria will be identified through multiple sources, including abstracts, bibliographies (in any language), databases (

Data Collection and Analysis
A coding protocol will be prepared along the guidelines of the Campbell Collaboration. The main purpose of the review will be to identify comparisons of reoffending rates among prisoners and those serving community-based sentences. The data analysis will be in line with current standards of meta-analyses (e.g. as specified in Practical Meta-Analysis by Lipsey & Wilson). However, the techniques to be used will be decided upon once the number of studies meeting the eligibility criteria is known. It is indeed not certain whether sufficient data will be available to justify more complex data analyses. If feasible given the number of studies identified, we shall look also at potentially important moderator variables, such as the profile (gender, age, SES, ethnic background) of persons sentenced to different sanctions, the nature of alternatives and the length and type of imprisonment. In this context, we also would like looking at potential effects of local environments (urban vs. rural, or different cultural orientations of countries).

Methods of the review
Both reviewers will identify potentially eligible studies. In case of disagreement about whether or not a study should be included, Professor Ulla Bondesson will act as arbitrator. Each study will be rated according to its methodological quality: (1) In the case of randomized experiments, deviations from the randomization process, or high attrition rates, will be noted.
(2) In the case of quasi-randomized experiments, special attention will be given to the independence of the selection criteria from offender characteristics.
(3) In case of non-randomized studies, the theoretical and/or practical relevance of the control variables will be considered.
In case of disagreement between the reviewers, aribtration will be sought.
Meta-analytic data analysis techniques will be proposed once the number and quality of studies to be included is known. At the moment, it is difficult to guess how many studies will be identified.

Timeline
The review should be completed within one year, in line with the guidelines of the funding agency (National Science Foundation of Switzerland). Updating of the review will be done regularly (every five years, or more frequently, according to the expected number of future research reports).

Statement concerning conflicts of interest
The reviewers have no personal, material, or academic interest whatsoever in the outcomes of the review.
Both have published work which is supportive as well as critical of alternatives to imprisonment. Financial support by the National Science Foundation of Switzerland does not affect the independence of the reviewers.