Introduction

Parole is crucial for preparing people in prison for reintegration into society. It can serve as a crucial motivator encouraging individuals to engage in rehabilitative and other therapeutic interventions to demonstrate their commitment and readiness for release (Ostermann, 2011; Vîlcică, 2018). Re-entry services aim to ease the transition to the community, providing additional support for those exiting incarceration (Ostermann & Hyatt, 2016). Parole is also important for public safety, with research from several countries showing that parolees are less likely to reoffend than their unconditionally released counterparts (Ellis & Marshall, 2000; Stavrou et al., 2016; Vito et al., 2017; Wan et al., 2014). Additionally, parole is beneficial for reducing the length of incarceration, addressing prison overcrowding, and freeing up resources for the remaining inmate population (Ellis & Marshall, 2000; Ostermann & Hyatt, 2016). It offers a cost-effective alternative to imprisonment, with annual expenses reported to be over twenty times higher for incarceration than community supervision (Queensland Productivity Commission, 2019).

Despite parole’s benefits, correctional services in several countries with discretionary release systems have observed a rising trend of incarcerated individuals choosing to forgo opportunities for parole (Cabana et al., 2009; Ostermann, 2011; Taylor, 2016). Depending on the jurisdiction, this may occur through two primary avenues. Firstly, some people in prison may automatically qualify for parole after their non-parole period. In such cases, the person may opt to postpone or waive scheduled hearings (Lord et al., 2021). Alternatively, those eligible for parole may need to formally apply to the relevant parole authority for their case to be evaluated. In this scenario, a person could relinquish their right to seek parole by not applying or withdrawing an application later (Ostermann, 2011). Consequently, parole processes can allow people in prison to opt for serving their maximum term and securing unconditional release. These individuals, known as ‘maxing out’ from prison or ‘opting out’ of parole, represent a unique population who remain incarcerated due to self-selection rather than a parole authority’s decision (Williamson, 2009).

In some jurisdictions, individuals who max out of prison will “remain incarcerated until their next hearing, their statutory release, or the end of the sentence, depending on the correctional system” (Lord et al., 2021, p.70). This often means that these individuals are released to the community unconditionally and with no supervision or oversight by correctional authorities (Lord et al., 2021). In other jurisdictions, mechanisms are in place to facilitate community supervision. For example, individuals who are denied parole by Canada’s National Parole Board become eligible for statutory release after completing two-thirds of their sentence unless board members establish the person is a high-risk of committing further serious offences (Guiney, 2023). In France, a form of ‘constraining release’ (liberation sous contrainte) was introduced in 2014 with the intention of achieving the release of people in prison who did not apply for an earlier form of release (débat contraditoire) (Herzog-Evans, 2019).

Globally, research indicates a growing trend of people in prison opting out of parole. In the United States (US), a study found that 40 per cent of New Jersey inmates waived their parole hearing (Ostermann, 2011). In Canada, 45 per cent of federal inmates waived their entitlement to seek parole (Cabana et al., 2009). In Australia, the Adult Parole Board in Victoria reported a 200 per cent surge between 2012 and 2016 in the number of people in prison serving their maximum sentence despite parole availability (Taylor, 2016). These trends potentially reflect the heightened politicisation of parole in many countries, as well as legislative or policy changes that have made the process of seeking, being granted, and completing parole more difficult than before (Freiberg et al., 2018; Moffa et al., 2019). These trends may also reflect people in prison’s perceptions or experiences of parole processes as a mechanism to impose further punishment on them, with Vîlcică’s (2018) research suggesting that parole decision-makers use parole for punitive objectives.

This paper presents the findings of a systematic review that synthesises global research on the issue of people in prison who forgo parole. Opting out of parole has significant implications for correctional systems, incarcerated people and their prospects of rehabilitation and reintegration, and broader public safety concerns (Lord et al., 2021). Despite these implications, Lord et al. (2021) highlight the scarcity of studies on this subject and note that existing research is impacted by limited scopes and methodologies. Additionally, there is a lack of comprehensive analyses concerning females and First Nations peoples in prison (Lord et al., 2021). Thus, there is a need to establish the current knowledge base regarding individuals in prison who forgo parole to identify gaps in understanding and avenues for future research. This research aims to provide valuable insights for practitioners and policymakers, potentially aiding in the development of strategies to more effectively encourage incarcerated individuals to consider pursuing opportunities for parole.

Parole: An Increasingly Politicised Process

Parole is a form of conditional release that allows individuals convicted and sentenced to imprisonment to serve all or part of their sentence in the community under supervision and specified conditions (Bartels et al., 2018). Parole serves as the primary ‘back-end’ criminal justice policy providing for post-release supervision, behavioural monitoring, and therapeutic and rehabilitative programming (Ostermann & Hyatt, 2016). It is known globally by various names, including conditional release, discretionary release, and release on licence.

There are generally two types of parole release – mandatory and discretionary. Mandatory, or court-ordered, parole refers to a predetermined period of post-release supervision that is integrated into the original sentence and is independent of a release authority’s decision (Ostermann & Hyatt, 2016). Discretionary, or board-ordered parole, occurs when a parole authority assesses an incarcerated person’s readiness for return to the community. The parole authority’s decision to grant parole enables that person’s conditional release, allowing them to serve the remaining sentence in the community (Fitzgerald et al., 2016). It is in jurisdictions with discretionary parole where people in prison may influence parole outcomes by not apply for parole or choosing to waive their parole board hearing (Best et al., 2014).

As the “sole gatekeeper between the prison and the community” (Huebner & Bynum, 2006, p. 963), parole authorities are crucial decision-makers and play a critical role in criminal justice systems (Fitzgerald et al., 2023). However, concerns have been raised about the limited judicial oversight and comparatively lower standard of review for parole authorities than other criminal justice decision-making bodies (Hritz, 2021). This potential lack of scrutiny may allow individual biases of board members to influence decisions (Hritz, 2021), contributing to disparities in release determinations (Ruhland, 2020). Hritz (2021, p. 336) emphasises that parole authorities’ discretion means they can “effectively reverse trial court findings regarding the seriousness of the offense and increase the time an individual will serve in prison”. Indeed, research by Vîlcică (2018, p. 1374) found support for the idea that parole boards may embrace their role as “second-round judges” and use parole for punitive means. This could result from pressures on parole authorities to adjust their decision-making practices; pressures that can intensify within changing and oftentimes volatile political environments and amid media and public pressure (Vîlcică, 2018).

In recent years, parole has become increasingly politicised (Freiberg et al., 2018; Moffa et al., 2019). Trends in ‘parole populism’ (Moffa et al., 2019) have followed high-profile parole crises moments internationally, such as the Jill Meagher murder in Melbourne, Australia (Freiberg et al., 2018), the John Worboys case in the United Kingdom (Fitzgerald et al., 2023), and the Marc Dutroux case in Belgium (Bauwens et al., 2012). Heightened political and public scrutiny following such events has led to political and legislative interventions that often restrict parole board discretion and adopt more risk-averse approaches to parole (Fitzgerald et al., 2023; Freiberg et al., 2018). In one of the more extreme political responses, a moratorium was imposed on all parole releases for a six-month period between 2008 and 2009 in Pennsylvania, US, following instances of violent offending by recently released parolees (Vîlcică, 2016). Changes to the parole landscape have eroded the rights of incarcerated persons (Guiney, 2023) and raised concerns about the legitimacy of parole (Chen et al., 2024). Those in prison are also likely aware of the evolving parole landscape and the challenges in obtaining favourable decisions. Research shows that, following parole hearings, frustration (55%) and anxiety (27%) are the most common emotions reported, with only 19% expressing hope for a positive outcome (Kelly et al., 2020). Recent research highlighted the impacts of the Pennsylvanian moratorium on people in prison, with Chen et al. (2024) reporting an erosion in trust in parole processes and significant impacts on individuals’ wellbeing.

Present Study

This study is a systematic review that seeks to provide a comprehensive and systematic display of the existing empirical research on people in prison who forgo the opportunity for parole. Employing a Mixed Methods Research Synthesis, it systematically reviews “empirical qualitative, quantitative, and mixed methods studies in shared domains of research aimed at aggregating, integrating, or otherwise assembling their findings via the use of qualitative and/or quantitative methods” (Sandelowski et al., 2007, p. 99). The review answers the following research questions:

  1. 1.

    What factors (e.g., individual characteristics, offending-relating factors, and broader system factors) are associated with people in prison forgoing parole eligibility?

  2. 2.

    What motivates people in prison to waive their eligibility for parole?

  3. 3.

    Is the decision to forgo parole related to recidivism outcomes?

Methods

This systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (Moher et al., 2009). A protocol for the research was registered with the Open Science Framework in October 2022.Footnote 1

Search Strategy

The search strategy encompassed 10 platforms across 22 databases, eight additional journals, and 31 websites/research repositories in August and September 2022 (see Supplemental Table A for all search locations). Databases were searched on three sets of keyword terms relating to ‘parole’, ‘prison’, and ‘forgoing parole’ (see Supplemental Table B). Terms within each set were combined using Boolean OR operators, and the three sets were then combined with Boolean AND operators. These search terms were intended to be very specific to locating documents relating to research on parole waivers and, as a result, have excluded literature related to broader, but related, topics.Footnote 2

Inclusion Criteria

Several criteria were applied to determine the eligibility of documents for inclusion in this review (see Table 1). Importantly, these criteria included that while documents could emanate from any geographic location, they had to be written in English. This requirement was necessary due to the resources needed to identify, obtain, and translate non-English language documents (Pham et al., 2005). However, this language restriction represents an important limitation of this research, as it may exclude relevant documents on this topic written in other languages (White & Schmidt, 2005). Consequently, this study may not capture a comprehensive global perspective of the evidence surrounding parole waivers and instead may primarily reflect a Western context (Stern & Kleijnen, 2020).

Table 1 Eligibility Criteria
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Identifying Relevant Studies

Covidence, a web-based reference management software, facilitated the review’s information management, allowing for the importation and screening of citations and full-text articles, identification of duplicate entries, resolution of conflicts, and data extraction using customisable forms (Cleo et al., 2019). Employing a two-stage screening process, the first stage involved reviewing titles and abstracts to exclude ineligible studies based on the inclusion criteria. Documents meeting the inclusion criteria progressed to literature retrieval before full-text screening in the second stage. Forward and backward citation searches of eligible documents were undertaken and identified experts in the field were contacted to locate any potentially eligible unpublished studies. To ensure interrater reliability, two review authors and a research assistant completed screening tests, with a 93% initial agreement rate and disagreements resolved through discussion.

Data Extraction and Analysis

The research team created a Covidence coding scheme form to guide data extraction, covering three domains: (1) study information; (2) factors relating to decisions to forgo parole; and (3) prisoner motivations for waiving parole (see Supplemental Table C). Adopting a Convergent Synthesis Design, evidence—whether qualitative, quantitative, or mixed methods—was collected and analysed in a parallel manner (Hong et al., 2017). Results were integrated using a data-based convergent synthesis design (Hong et al., 2017), where all studies are analysed using the same synthesis method and the results presented together. Since only one method of synthesis is used for all evidence, this approach typically involves transforming the data (for example, from quantitative data into categories/themes) (Hong et al., 2017). A meta-synthesis approach was then applied to analyse the data, identifying key themes that provide strong explanations for the phenomenon being studied (Siddaway et al., 2019). This approach involved analysing all studies in this review (regardless of the methods they use) through a thematic lens, identifying key themes that enhance understanding of the issue of people in prison who forgo parole.

Quality Appraisal

The Mixed Methods Appraisal Tool (MMAT) (Hong et al., 2018) was used to assess article quality in this review since it accommodates qualitative, quantitative, and mixed methods studies within a single tool (Pace et al., 2012). The research assistant employed MMAT for the initial appraisal of the included articles. To ensure accuracy and reduce bias, the two review authors independently appraised a randomly selected sample (60%) of the included articles using the MMAT. An overall rating per article was calculated by summing scores (1 = ‘yes’, 0 = ‘no’ or ‘can’t tell’) from the five MMAT criteria (5 = highest, 1 = lowest), excluding the two screening questions (e.g., Bjornseth & Szabo, 2018; Dodd et al., 2023) (See Supplementary Tables D and E). Inter-rater reliability was assessed for each MMAT item and calculated as a percentage rate of agreement (Chaturvedi & Shweta, 2015). The initial agreement rate between was 92%. A secondary appraisal resolved differences in ratings until 100% agreement was reached.

Results

Search Results and Screening

Our search yielded 26,540 records (see Fig. 1 for the literature search process flowchart). The majority (n = 22,091) of studies from the initial searches were deemed ineligible after the first screening round. Many duplicates were also identified (n = 4,436). A total of 23 records remained after scanning the title and abstracts, and full texts for these records were retrieved. Screening the full texts led to 19 documents, representing 18 studies, being judged eligible for inclusion in this review. These 18 studies were included in the final analysis.

Fig. 1
figure 1

Flowchart of the literature search process

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Study Characteristics and Data Sources

Studies included in this review exclusively reported on North America, with nine studies from the US, eight from Canada, and one using a sample from both countries (see Table 2). Most of the studies were reported in journal articles (n = 8), followed by reports (n = 7), and theses or dissertations (n = 3). Quantitative research designs were predominant, comprising 83% (n = 15) of the studies, while qualitative approaches constituted 11% (n = 2), and one study used a mixed-methods approach. Approximately 60% of studies were published before 2010, with the remaining 39% from 2010 onward.

Table 2 Included Studies’ Characteristics (n = 18)
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Most studies (83%) relied on administrative data, sourced from offender management systems maintained by corrective services agencies. Interviews were used in three studies, while surveys, focus groups, and ethnography were rare. Of the included articles, 94% (n = 17) met the MMAT appraisal criteria.Footnote 3 The average MMAT score for the included articles was 4.82 ± 0.73 (96%) (see Supplemental Table D).

Factors Associated with Forgoing Parole

Understanding factors related to forgoing parole is crucial for developing targeted interventions and support programs for high-risk groups. We therefore begin our analyses of the eligible studies by examining the factors that research has considered when examining individuals in prison who waive parole (n = 14). We broadly categorise these factors into five groups: (1) demographic features; (2) mental health, wellbeing, and disability indicators; (3) offence type and offending history; (4) correctional experience; and (5) the release environment. Below, we present results from eligible studies in this review, highlighting factors associated with an increased or decreased likelihood of individuals waiving parole.

Demographic Factors

Gender

Nine studies explored the impact of gender (typically measured as a binary) on parole waiver decisions (Cabana & Ruddell, 2010; Cabana et al., 2009; Keown et al., 2015; Lord et al., 2021; Matejkowski & Ostermann, 2021; Ostermann, 2009, 2011, 2012; Williamson, 2009). Their findings are somewhat mixed. Williamson (2009) reported that male inmates were twice as likely to forgo parole compared to females, aligning with Cabana et al.’s (2009) finding of a statistically significant difference between male (56%) and female offenders (35%) in their likelihood of waiving, postponing, or withdrawing a parole review. Ostermann (2009, 2011) similarly observed males as significantly overrepresented among voluntary max-outs compared to parolees.

Other studies found no gender-based differences in parole waiver decisions (Cabana & Ruddell, 2010; Keown et al., 2015; Matejkowski & Ostermann, 2021). Interestingly, while Lord et al. (2021) reported no significant gender differences in parole waiver rates, their moderation analysis revealed that for shorter sentence lengths (i.e., 6.6 months), females were significantly more likely to waive parole eligibility (48%) compared to males (39.2%). Conversely, for longer sentences (i.e., 18.3 months), males were much more likely to forgo parole (34.1%) than females (22.5%). Descriptive comparisons by Ostermann (2012) showed voluntary max-outs were slightly less likely to be male (90%) than the discretionary parolee group (92.3%).

Age

Seven studies investigated the link between age (at onset or release) and forgoing parole (Lord et al., 2021; Matejkowski & Ostermann, 2021; Ostermann, 2009, 2011, 2012; Schlager & Robbins, 2008; Williamson, 2009). Ostermann (2011) found voluntary max-outs were, on average, significantly older at release (35.49 years) compared to parolees (33.58 years). However, voluntary max-outs were significantly younger (20.66 years) at their first arrest compared to parolees (21.75 years), aligning with other studies’ findings, except for Lord et al. (2021). These findings align with expectations, as inmates maxing out and spending more time in prison are likely older than comparative groups. More notable, however, is the finding that inmates who max out from prison were significantly younger at their first arrest, suggesting potentially more chronic offending trajectories.

Ethnicity/Race

Eight studies explored the impact of ethnicity or race on parole waiver decisions (Cabana & Ruddell, 2010; Farrell MacDonald, 2017b; Lord et al., 2021; Matejkowski & Ostermann, 2021; Ostermann, 2009, 2011; Welsh & Ogloff, 2000; Williamson, 2009). These studies examined whether ethnic minorities are more or less likely to forgo parole than their white or non-Indigenous counterparts. In a US study, Williamson (2009) compared parolees with inmates who waived parole, finding that Black inmates were half as likely as White inmates to forgo parole (once all controls were considered). However, other US studies found no significant differences by race/ethnicity (Matejkowski & Ostermann, 2021; Ostermann, 2009, 2011).

Canadian research on Indigeneity and parole waiver decisions indicates significant disparities. Lord et al. (2021) found Indigenous people were twice as likely to waive parole compared to non-Indigenous counterparts. Welsh and Ogloff (2000) reported a lower parole application rate among Aboriginal offenders (47.7%) compared to non-Aboriginal offenders (73.5%). Moreover, Aboriginal offenders were more likely to waive a hearing for full parole (58.8% vs. 33.1%). Cabana et al. (2009) noted Aboriginal offenders were more likely to delay or cancel parole reviews, although a slightly higher proportion of non-Aboriginal offenders postponed reviews. In a follow-up study, Cabana and Ruddell (2010) found Aboriginal offenders slightly less likely to experience multiple parole delays or cancellations than Caucasian and Black inmates. Farrell MacDonald (2017b) highlighted gender and Indigeneity intersections, with Indigenous women exhibiting the highest rate of review delays or cancellations (50%). Within Indigenous groups, Inuit inmates were more likely to delay or cancel their parole review (68%) than either First Nations inmates (61%) or Métis inmates (57%).

Education and Employment

Four studies considered employment and education’s impact on decisions to forgo parole (Cabana et al., 2009, 2011; Lord et al., 2021; Williamson, 2009). These studies indicate that individuals unemployed at the time of their offence (Lord et al., 2021) or frequently unemployed (Williamson, 2009) were more likely to waive parole. Further, inmates with lower education levels were more prone to delaying a parole review (Cabana et al., 2011) or waiving, postponing, or withdrawing their parole application (Cabana et al., 2009). Yet Lord et al. (2021) found no significant impact of education on waiver decisions once accounting for all variables in their hierarchical logistic regression models.

Relationship Status and Quality

Only two studies including variables capturing relationship status/quality were identified. Ostermann (2012) reported that voluntary max-outs (81%) were marginally less likely to be single than discretionary parolees (82.7%) (though no significance levels were assessed). Williamson (2009) considered whether dissatisfaction with marital relationships was related to waiving parole, however, the results were not statistically significant.

Mental Health, Wellbeing, and Disability Indicators

Four studies considered the impact of mental health, wellbeing, and/or disability on the likelihood of waiving parole. Matejkowski and Ostermann (2021) found that inmates with mental illness had 21% higher odds of waiving parole compared to those without mental illness. Cabana and colleagues (2011) similarly identified a higher likelihood of parole review delay among inmates with mental deficiencies or mental health diagnoses. Their previous study also showed that inmates with high needs in personal/emotional functioning or substance abuse issues were more likely to waive, postpone, or withdraw parole applications compared to offenders without such needs (Cabana et al., 2009). Williamson (2009) similarly reported a higher likelihood of parole waiver among inmates with psychological or emotional problems, negative attitudes/orientation scale, or substance indicators, although a current drug or alcohol problem was not significantly associated with forgoing parole.

The impact of disability on parole waiver is less studied, with Cabana et al. (2011) finding that inmates with a learning disability or reading/numeracy difficulties were more likely to delay or cancel their parole review compared to inmates who attended their parole review.

Offence Type and Offending History

Instant Offence Characteristics

Research (n = 9) has also examined the number and type of instant offences for individuals who waive parole (Cabana et al., 2009; Farrell MacDonald, 2017a; Lord et al., 2021; Matejkowski & Ostermann, 2021; Ostermann, 2009, 2011, 2012; Schlager & Robbins, 2008; Williamson, 2009). Ostermann (2011) reported that parolees (50.3%) were more likely to have just one instant offence conviction compared to maxed out offenders (39%), while voluntary max-outs were more likely to have four or more instant offence convictions (21.7%) compared to parolees (12%). Cabana et al. (2009) reported that those waiving, postponing, or withdrawing from parole consideration were twice as likely to be incarcerated for at least two offences compared to comparison group offenders.

Research findings are mixed as to whether offence type influences the likelihood of waiving parole. Schlager and Robbins (2008) reported that those maxing out of prison are more likely to be incarcerated for violent offences and less likely for drug offences. Ostermann (2012) found that voluntary max-outs were more likely than parolees to be imprisoned for property, violent, or sex offences, but less likely to have drug convictions. Similarly, Cabana et al. (2009) found that those waiving, postponing, or withdrawing from parole (83%) were more likely to be serving a sentence for a serious offence than comparison group offenders (69%). Recent research by Lord et al. (2021) also found that individuals with drug or “other” offences were less likely to waive parole than those with offences against a person. Farrell MacDonald (2017a) reported that Indigenous offenders waiving parole were more likely to have committed a violent offence.

However, other research suggests it is non-violent offenders who forgo parole. Matejkowski and Ostermann (2021) found a significantly greater proportion of individuals opting out of parole were imprisoned for property crimes, with smaller proportions for drug, sex, or violent crimes. Similarly, Williamson (2009) found that individuals with a most recent conviction for a violent offence were approximately 1.4 times less likely to forgo parole. In contrast to other research, Ostermann (2009) found no variation in crime type between voluntary max-outs, involuntary max-outs, or parolees.

Risk Classification

Studies exploring the relationship between a prisoner’s risk classification/ score and likelihood of waiving parole (Cabana & Ruddell, 2010; Cabana et al., 2009, 2011; Lord et al., 2021; Matejkowski & Ostermann, 2021; Ostermann, 2009, 2011, 2012) consistently show that higher-risk offenders are more likely to waive parole. Recent research reported that individuals with a higher risk assessment were more likely to forgo parole, with the likelihood increasing by 7.7% for each additional unit on the Level of Service/Case Management Inventory score (Lord et al., 2021). Further, Matejkowski and Ostermann (2021) observed that prisoners who waived parole were more commonly medium and high-risk offenders, and less likely to be low-risk offenders. Cabana and Ruddell’s (2010) research revealed that offenders waiving, postponing, or withdrawing a parole review are generally high risk and need, with the highest risk and need offenders tending to waive their parole reviews rather than repeatedly delaying them. Similar findings on the relationship between risk and the increased likelihood of waiving, postponing, or withdrawing from parole have been reported elsewhere (e.g., Cabana et al., 2009, 2011; Ostermann, 2009, 2011, 2012).

Prior Arrests, Convictions, and Incarceration

Research consistently shows that individuals who max-out from prison have a more extensive criminal history, including prior arrests, convictions, and periods of incarceration (Farrell MacDonald, 2017b; Ostermann, 2009, 2011; Schlager & Robbins, 2008; Williamson, 2009). Schlager and Robbins (2008) reported that compared to parolees, max-outs had a significantly higher number of prior arrests (8.6 arrests v 10.1 arrests). Similarly, Ostermann (2011) reported that voluntary max-outs (10.69) had more prior arrests than parolees (7.82), as did Ostermann (2009).

Studies also show that individuals who waive parole tend to have a larger number of prior convictions and periods of incarceration. Ostermann (2009, 2011) reported that max-out prisoners had a greater number of prior convictions compared to parolees. Schlager and Robbins (2008) found that prisoners who forgo parole had been previously incarcerated significantly more often than parolees (1.7 times v 1.1 times). Further, Canadian research focusing on low-risk offenders found that Indigenous offenders who waived, postponed, or withdrew from parole, were more likely to be serving their second or subsequent sentence when compared to non-Indigenous offenders (Farrell MacDonald, 2017b). However, past convictions were not significantly associated with opting out in Williamson’s (2009) full models.

Correctional Experience

Sentence Length, Time Served, and Security Level

Conflicting findings arise from studies assessing the impact of sentence length and time served on the likelihood of waiving parole (Cabana et al., 2009; Farrell MacDonald, 2017a; Lord et al., 2021; Matejkowski & Ostermann, 2021; Ostermann, 2009, 2011). Recent research suggests that longer sentences are associated with a lower likelihood of waiving parole (Lord et al., 2021). However, a prior study found that offenders who waived, postponed, or withdrew their first parole review were serving longer sentences relative to comparison group offenders (4.6 years v 3.6 years) (Cabana et al., 2009). Farrell MacDonald (2017a) reported that Indigenous offenders who waived parole were more likely to have shorter sentences compared to Indigenous offenders who did not waive parole and were less likely to be in minimum security. Ostermann (2011) reported that voluntary max-outs served a greater amount of time for their instant offence than parolees (1297.49 days v 973.34 days), though days sentenced were not significant. For Ostermann (2009), neither days served, nor days sentenced, were significantly associated with voluntary max-outs. More recently, Matejkowski and Ostermann (2021) found no impact of time served on parole waiver decisions.

Institutional Misconduct

Seven studies explored the impact of institutional misconduct on parole waiver decisions (Cabana et al., 2009, 2011; Farrell MacDonald, 2017a; Lord et al., 2021; Ostermann, 2009, 2011; Williamson, 2009). Overall, this research suggests that individuals with a history of problematic institutional behaviour are more likely to forgo parole. Williamson (2009) reported 84% increased odds of opting out of parole for those with a record of prison misconduct, while those with a history of assault or violence in prison were 2.5 times more likely to waive parole. Ostermann (2009, 2011) similarly found that parole-waiving individuals had more disciplinary infractions, while Cabana et al. (2009) found that they were twice as likely to be instigators of institutional misconduct. Later research by Cabana et al. (2011) showed that offenders delaying their parole review had significantly more segregation admissions than offenders who appeared before the Parole Board. Focusing on Indigenous offenders, Farrell MacDonald (2017a) found a higher likelihood of problematic institutional behaviour among those who waived parole. However, Lord et al. (2021) found no significant relationship between parole-waiving decisions and institutional misconduct after accounting for other factors.

Participation in Rehabilitative Programs

Research has also examined the relationship between program completion and parole waivers, generally finding that program non-completion is a relevant factor in prisoners’ decisions (Cabana et al., 2009; Cabana & Russell, 2010; Cabana et al., 2011; Farrell MacDonald, 2017a; Ostermann, 2009, 2011). Cabana and Ruddell (2010) reported that 41.3% of parole-waiving decisions were due to incomplete rehabilitative programs, along with 39.4% of decisions to postpone parole, and 23.8% of decisions to withdraw from a parole hearing. Similar findings were observed in Cabana et al.’s (2009) earlier research, where parole officers most frequently cited program-related issues as the reason offenders chose not to appear before the Parole Board. Ostermann’s (2009, 2011) analyses confirmed that, compared to parolees, voluntary max-outs were significantly less likely to have participated in prison programs. However, program completions were non-significant (Ostermann, 2011).

Additional context for program non-completion reasons is provided by Cabana et al.’s (2011) research. Their analysis showed that both offender-related and administrative factors helped to explain why offenders had incomplete programs before their scheduled parole hearings. Offender-related reasons included suspensions from programs due to participation issues, offender refusal of the initial program offer, and inability to participate due to being in segregation. Administrative factors included program cancellations or unavailability for offenders serving short sentences (Cabana et al., 2011).

Prior Supervision on Parole

Several studies suggest a relationship between prior community supervision experience and forgoing an opportunity for parole (Cabana et al., 2009; Lord et al., 2021; Ostermann, 2011; Schlager & Robbins, 2008; Williamson, 2009). Schlager and Robbins (2008) reported that max-outs were significantly more likely to have been paroled previously (1.4 times) than parolees (0.8 times). Similarly, Ostermann (2011) reported that, compared to parolees, voluntary max-outs were significantly more likely to have experienced a previous parole release and technical parole violation. This coincides with Cabana et al.’s (2009) finding that individuals forgoing parole were significantly more likely than comparison group offenders to have prior parole experience and a failed release. Lord et al.’s (2021) moderation analysis showed that Indigenous people with previous community sentence experience had a lower probability of waiving, while experience with a community sentence was not significant for non-Indigenous people. Lastly, Williamson (2009) considered the impact of the suspension of prior probation/parole on decisions to opt out, however, this factor was not significant.

Release Environment

Only one study explored the effect of the broader release environment (such as family and community factors) on decisions to forgo parole. Williamson (2009) reported that individuals in prison with criminal family members or spouses were less likely to waive parole. Interestingly, Williamson (2009) also considered whether the offender was socially isolated, lived in a high-crime neighbourhood, reliant on social assistance, or had changed their address three or more times in the previous year. All were non-significant.

Motivating Reasons for Forgoing Parole

Promoting parole engagement becomes challenging without a thorough understanding of the reasons that may foster or hinder individuals’ participation. Insight into motivating factors behind parole waiver decisions can help to identify structural barriers and biases that may influence individuals’ decision-making processes. Consequently, our second research question explores the motivating reasons for individuals in prison to forgo the opportunity for parole. While 14 studies in this review focus on factors associated with forgoing parole, limited research explores motivating reasons (n = 8). Despite the qualitative nature of this question, only three studies (Best et al., 2014; Cabana et al., 2009; Polowek, 2005) used qualitative methods to explore reasons why people in prison decide to forgo parole. The remaining five studies (Farrell MacDonald, 2017a, 2017b; Keown et al., 2015; Lord et al., 2021; May & Wood, 2005) were based on quantitative analyses.

Best and colleagues (2014) identified four primary reasons for forgoing parole using semi-structured, in-depth interviews with 25 parole-eligible adult male inmates who had waived their parole hearing. Most commonly, prisoners expressed a preference not to be released on parole, citing perceptions that prison life was easier than parole supervision and, less often, fears of parole revocation. Many inmates also identified that they had waived parole because of their reluctance to participate in the parole hearing, anticipating a parole denial or negative experience. The third reason related to inmates’ hesitance to re-enter the community, driven by concerns of facing stigma and other re-entry barriers. Lastly, some inmates noted they were advised to waive parole by their caseworkers, family, friends, or fellow inmates.

Other studies echo similar themes, including that inmates waive parole to sidestep an unfavourable decision (Farrell MacDonald, 2017a, 2017b). May and Wood’s (2005) study indicated that many inmates perceived parole and program officers as excessively stringent, aiming to ‘catch them and send them back to prison’. This reason was deemed ‘very important’, with 46.4% of participants stating it as a reason to avoid alternative sanctions, like parole. Cabana et al. (2009) found that 35% of inmates identified a perceived lack of support from their parole officer or case management team. Indeed, Lord et al. (2021) reported that the likelihood of waiving parole was four times lower for a person who had received a positive parole officer recommendation.

According to Keown et al. (2015), motivating reasons differ by gender, with male prisoners more likely to waive or withdraw to avoid a negative decision whereas female prisoners were likely to cite ‘other’ reasons. Farrell MacDonald’s (2017a) research revealed that irrespective of Indigenous group, risk level, or gender, Indigenous offenders most often cited program non-completion as the reason for waiving or withdrawing from their parole review. Finally, Polowek (2005) reported that 29% of parole board members believed inmates postponed or waived parole due to the presence of victims at the parole hearing.

Recidivism Outcomes

Studies typically find favourable recidivism outcomes for supervised offenders compared to those released unconditionally (Ooi & Wang, 2022; Ostermann & Hyatt, 2016; Vito et al., 2015). These findings highlight the potential benefits of supervised release programs for reducing reoffending and enhancing community safety. As the third research question, we therefore considered research examining reoffending differences between voluntary max-outs and other groups (such as involuntary max-outs and/or parolees). Of the studies included in this review, five reported on recidivism outcomes.Footnote 4

The earliest identified study on the impact of waiving parole on recidivism outcomes was conducted by Ostermann (2011). Using three years of data for former New Jersey inmates, he explored reoffending rates for three cohorts: inmates who voluntarily opted out of parole, those unconditionally released due to continual parole denials, and parolees. Results indicated no statistical differences in reoffending rates between voluntary max-outs and involuntary max-outs or parolees.

Ostermann’s (2012) later research used propensity score matching to compare reoffending patterns for voluntary max-outs and parolees in New Jersey. Results showed that a significantly greater proportion of voluntary max-outs were rearrested and/or reconvicted (66.5%; 56.2%) during the three-year follow-up period compared to parolees (61.9%; 47.8%). Voluntary max-outs also had a significantly greater number of arrests and convictions (1.74; 1.34) compared to parolees (1.44; 0.96) and accrued these approximately three months sooner.

Schlager and Robbins (2008) similarly reported higher proportions of rearrest (70%) and reconviction (44%) among New Jersey max-outs compared to parolees (60% rearrested, 34% reconvicted). Further, parolees remained free from rearrest significantly longer than maxed-out offenders. Williamson’s (2009) study showed that inmates who opted out of parole were more than four and a half times as likely to be rearrested during their first year of discharge compared to parolees.

Finally, Matejkowski and Ostermann (2021) investigated the relationship between mental illness, the choice to waive parole consideration, and reoffending. Results showed that both inmates with and without mental illness who voluntarily maxed-out of prison had approximately 31% higher hazards of rearrest compared to mentally ill parolees. Thus, they concluded that recidivism outcomes were more closely linked to parole supervision presence/absence than the presence/absence of mental illness.

Discussion

Parole serves as a potential motivator for incarcerated individuals to engage in rehabilitative interventions (Ostermann, 2011). It also offers a cost-effective alternative to imprisonment, promoting public safety and relieving pressure on overcrowded and under-resourced correctional facilities (Ellis & Marshall, 2000; Ostermann & Hyatt, 2016). Evidence suggests, however, a growing trend amongst people in prison to forgo parole, meaning they ‘max out’ from prison at the end of their sentence without any conditions or supervision requirements (Cabana et al., 2009; Ostermann, 2011). Parole waivers have serious implications, both for people in prison and society (Lord et al., 2021). This Mixed Methods Research Synthesis comprehensively reviews existing empirical research on individuals who waive parole. Our findings have important implications for future research and policymaking.

This review shows there is a small body of research on the topic of parole waivers, with just 18 identified studies and a geographic distribution confined to the US and Canada (albeit noting this review only included English-language research). This is not surprising since a considerable amount of parole research emanates from North America (Lord et al., 2021). However, variations of discretionary parole systems also exist in countries like France, Belgium, England, Australia, and New Zealand (Best et al., 2014; Fitzgerald et al., 2023). As the criminal justice systems significantly differ between those countries and North America, the generalisability of existing research findings to other jurisdictions remains uncertain (Lord et al., 2021). Future research should, therefore, extend its focus beyond North America to uncover cross-cultural similarities and differences.

Further, most of the studies included in the review used quantitative analysis techniques (83%) and relied on administrative correctional data as their primary data source (83%). Less than half (44%) of the studies were published in peer-reviewed journal articles, with a substantial proportion being reports (39%) and theses or dissertations (17%). This underscores the necessity for additional rigorous research, including studies using qualitative research methods to elucidate the motives and disincentives influencing individuals as they weigh their re-entry options (Best et al., 2014). Furthermore, there is a notable research gap concerning the characteristics and motivations for waiving parole among women in prison and Indigenous persons, warranting more in-depth exploration (Lord et al., 2021).

Most studies identified in this review focus on the factors related to individuals in prison who choose to waive parole, revealing common characteristics among them. Notably, several studies suggest that those who waive parole are Indigenous, male, with a history of mental illness and/or substance addiction, and prior conditional release experience. They tend to be unemployed, possess low education levels, have extensive histories of imprisonment, and are considered high risk for reoffending. Additionally, these individuals are often serving long sentences and for violent offences, but frequently have not completed rehabilitative programs related to their offences. From a policy perspective, these findings raise concerns, as high-risk individuals could benefit significantly from reintegrative support and post-release supervision (Ostermann, 2011, 2012). As Best et al. (2014) argue, encouraging parole engagement among high-risk offenders is crucial for community safety and aligns with the established risk principle of correctional interventions targeting high-risk individuals.

Our findings also highlight several motivating factors for waiving parole, although this was notably an area with limited research. Two studies in this review used interviews with people in prison to explore reasons for hesitancy regarding parole processes (Best et al., 2014; Cabana et al., 2009). Best et al. (2014) identified several key reasons for parole waivers, including the perception that staying in prison is easier than parole supervision, reluctance to participate in parole hearings for fear of parole denial or negative experiences, and concerns about re-entering the community due to stigma and re-entry barriers. Other studies indicate incomplete rehabilitation programs and perceived lack of support from correctional and parole officers as additional factors for waiving parole (Cabana et al., 2009). Addressing these concerns could be focal point for correctional services and parole authorities to enhance people in prison’s engagement with parole processes (Best et al., 2014; Lord et al., 2021).

Research suggests that many people in prison may choose not to apply for discretionary parole because they believe their application will be unsuccessful (Best et al., 2014). This raises an important question: are these individuals unduly pessimistic or simply realistic about their chances for parole? According to research by Ostermann (2011), it is the latter. His analysis revealed minimal differences in criminal histories, participation in rehabilitative programs, and disciplinary infractions between individuals who chose to forgo parole and those who ‘maxed out’ due to repeated parole denials. Those with extensive criminal histories and prior violent convictions have a well-founded perception of their low likelihood of parole, as these factors are empirically linked to parole denials (Caplan, 2007; Vîlcică, 2018).

Consequently, efforts by correctional agencies to increase parole engagement may be futile if discretionary parole authorities maintain their current approach of denying parole to higher-risk individuals. These individuals, despite their higher risk, “would be in a position to gain the most benefit from being involved in the community-based programs that are traditionally offered through parole” (Ostermann, 2011, p. 705). Therefore, as Ostermann (2011) argues, the solution must lie in a dual approach: making parole more appealing for eligible individuals, while also urging parole boards to reconsider their decision-making practices to account for the potential benefits of parole for those who need it most. Only then are we likely to preserve both community safety and the intended purpose of discretionary parole as a means of assisting individuals to reintegrate into the community following a prison sentence (Chen et al., 2024; Ostermann, 2011).

Financial interests

The authors have no relevant financial or non-financial interests to disclose.