The study arrives at a moment of acute public anxiety in South Africa. Violent crimes such as cash-in-transit heists and mass shootings have increased substantially in recent years, dominating headlines and fueling debate about the effectiveness of policing and punishment. Yet the research draws attention to a quieter, less visible layer of criminality. Petty offences such as theft and burglary receive far less media coverage, but they remain pervasive and account for the majority of criminal cases in the country. Together, minor and major offences contribute to elevated public safety concerns and deepening doubts about whether the criminal justice system, as currently configured, is capable of delivering durable reductions in crime.

At the heart of the study is a concern that criminologists have long raised but that is rarely quantified at a national scale: imprisonment itself may, under certain conditions, intensify criminal behavior rather than suppress it. In South Africa, this concern takes on particular urgency because prisons are chronically overcrowded, and minor offenders are routinely housed alongside hardened criminals. The study argues that this mixing of populations creates environments that substantially elevate the risk of recidivism, meaning that a person convicted of a relatively minor offence may emerge from custody more deeply embedded in criminal networks and behaviors than before.

To test these ideas rigorously, Nyabadza built a mathematical model describing the population dynamics of individuals as they move among states defined by criminal behavior and rehabilitation status. Drawing on South African crime and prison data spanning 1995 to 2024, the model tracks pathways related to susceptibility, petty crime, serious crime, custodial sentencing, non-custodial sentencing, rehabilitation, and relapse. In this framework, a custodial sentence requires an offender to serve time locked in a prison or secure institution, while a non-custodial sentence allows the offender to remain in the community under specific rules and restrictions. By simulating how people flow between these states over time, the model can estimate how different sentencing policies alter the overall trajectory of criminal activity in the population.

The results are unambiguous in their direction. Indiscriminate custodial sentencing of petty offenders, the model shows, can amplify criminal activity across the system. By contrast, the risk that a petty offender escalates to serious crime is substantially lower when the person remains under community supervision. In other words, the pathway from a shoplifting or burglary conviction to involvement in violent or organized crime appears to run, at least in part, through the prison gate itself. The finding quantifies what has often been described anecdotally: that prisons in overcrowded conditions can function as schools for crime rather than institutions of reform.

According to the study author, the policy implications are clear. Evidence-based approaches that prioritize non-custodial rehabilitation, relapse prevention, and prison reform are described as essential for curbing recidivism and achieving durable crime reduction. Rather than reserving community sentences only for the least serious cases as a matter of leniency, the research suggests that keeping petty offenders embedded in their communities, with structured supervision and rehabilitation support, may be the more effective public safety strategy. This reframing positions sentencing reform not as a soft option but as a calculated intervention with measurable benefits for overall crime levels.

The study also illustrates how policy decisions leave detectable traces in national data. In a comment accompanying the research, Nyabadza noted that what struck him most was how clearly policy leaves its fingerprints in the data. He pointed to the sharp prison-population spike around 1999 to 2002, which coincided with the introduction of mandatory minimum sentencing, as an example of how legislative shocks can reveal insights that a smooth mathematical model alone cannot capture. That episode, in which a change in sentencing law produced a visible surge in incarceration, provides a natural experiment embedded in the historical record, allowing the model to capture the downstream consequences of abrupt policy shifts.

Like all modeling studies, this one carries important limitations that shape how its findings should be interpreted. The author notes that the results might not generalize to other countries, since the model is calibrated to South African crime and prison data and reflects the specific institutional conditions of that system. Pre-trial detention data are not included in the analysis, which could lead to an underestimation of criminal career duration, since time spent awaiting trial is invisible to the model. Additionally, the model allocates all released petty offenders to a high-risk class, a conservative assumption that may overestimate the escalation of criminal activity after release. These caveats mean the estimates should be read as indicative of direction and mechanism rather than as precise predictions for any individual case.

Further limitations concern what the model leaves out entirely. The methods do not capture the explicit socioeconomic drivers of crime, such as unemployment, inequality, or educational access, which are widely recognized as powerful influences on criminal behavior in South Africa and elsewhere. Nor does the study include a cost-effectiveness analysis of interventions, so while it can indicate that community-based approaches may reduce escalation, it cannot yet say how the financial costs of expanding non-custodial rehabilitation would compare with the costs of incarceration. These gaps define a clear agenda for future work, combining criminological modeling with economic evaluation and socioeconomic data to produce a fuller picture of the policy landscape.

Even with these constraints, the study offers a quantitative framework for one of the most consequential debates in South African criminal justice: what to do with the thousands of people convicted each year of petty offences. By translating the dynamics of sentencing, rehabilitation, and relapse into a formal mathematical structure, the research makes it possible to compare policy scenarios on a common footing and to see how choices made in courtrooms today ripple through prison populations and crime statistics for years afterward. The findings highlight the potential benefits of prison reforms that integrate deterrence with effective community-based rehabilitation, suggesting that the path to lower violent crime may begin with how the state responds to its least serious offenders. The full article is freely available in PLOS One for readers who wish to examine the model and its results in detail.

Subject of Research: Mathematical modeling of the criminogenic effects of incarcerating petty offenders in South Africa

Article Title: Incarceration may escalate criminal behavior in South Africa

Article References: Incarceration may escalate criminal behavior in South Africa. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: South Africa, incarceration, recidivism, petty crime, non-custodial sentencing, prison overcrowding, mathematical modeling, PLOS One, criminal justice reform, rehabilitation, mandatory minimum sentencing, crime policy

Penal populism first entered the scholarly vocabulary through the work of criminologist Anthony Bottoms, who described populist punitiveness as one of the main forces operating within contemporary criminal justice systems. The term captured how politicians, perceiving a deeply punitive public, pursue harsh penal policies for their own political gain. Later scholars broadened the concept. John Pratt described populism as a fundamental shift in the axis of penal power under the conditions of late modernity, while Mark Fenwick showed in the Japanese context that penal populism can also produce non-punitive policies, driven by an unmet demand for justice and security. What unites these accounts is the way penal policy becomes a reactive undertaking, supported not by evidence of effectiveness but by emotional resonance.

The authors illustrate the pattern with three contemporary cases. In the United States, following the murder of political activist Charlie Kirk, President Trump argued on Fox News for what he called quick trials, complaining that criminal proceedings stretching over seven or eight years allow defendants to blame their circumstances. The authors note that such statements run directly against the presumption of innocence and against criminology’s core mission of understanding why crimes are committed. In Morocco, public debate over Article 507 of the Penal Code, which prescribes life imprisonment for robbery involving a weapon, revealed how a broad statutory definition of a weapon, one that could in theory include a screwdriver, allows punishment to jump from a five-year maximum to life imprisonment, a severity that provoked a rare counter-movement by the mothers of convicted defendants. In India, the brutal 2012 gang rape and murder of a young woman known to the public as Nirbhaya generated massive protests and a government-appointed reform committee, yet the resulting 2013 criminal law amendments went further than the Verma Committee recommended, expanding the death penalty despite the committee’s explicit advice against it.

Across these cases, the authors identify a recurring architecture of claims. Populists insist the system is too lenient and demand severity. They place the victim and public safety at the center of debate, framed in zero-sum terms against legal safeguards. They reject criminological inquiry into the social determinants of crime as elitist indulgence. They position themselves as the authentic voice of ordinary people against out-of-touch experts. And they appeal to emotion rather than reason, mobilising outrage and fear as political capital. The murder of twelve-year-old Polly Klaas in 1993, framed as the loss of America’s innocent child, exemplifies how such emotional mobilisation can drive rapid legal change, producing California’s Three-Strikes law within months of the abduction.

The criminological case against these claims is stark. The most widely diffused populist assumption holds that harsher penalties deter crime because rational actors weigh potential gains against potential losses. Yet the empirical literature points the other way. Anthony Doob and Cheryl Webster’s examination of numerous studies found that most reviews do not support the claim that harsher sanctions deter, and the few studies that did were found to suffer from serious methodological or conceptual problems. Daniel Nagin’s assessment of deterrence research found that evidence for the certainty of punishment, particularly the probability of apprehension, is far more consistent than evidence for the severity of punishment. A meta-analysis by Travis Pratt and colleagues reached a similar conclusion, finding that the deterrent effects of formal legal sanctions are at best modest to negligible, and that punishment effects often shrink to zero when researchers control for factors such as self-control, peer influence, and antisocial attitudes. Strikingly, the most robust deterrents identified were informal sanctions such as shame and loss of respect, suggesting that fear of social costs outweighs fear of legal punishment.

Punitive sanctions do not merely fail to deter; they can actively undermine interventions that work. Mark Lipsey’s meta-analysis of 443 studies on juvenile delinquency treatment found that outcomes favoured treatment in 64.3 percent of studies, with the best programs reducing recidivism by ten to twenty percentage points. Some punitive interventions, notably deterrence-oriented programs such as shock incarceration and Scared Straight, produced negative effects, meaning that the tools promoted as making streets safer may be making them less safe. A review by Lipsey and Francis Cullen covering both juvenile and adult offending confirmed that supervision and sanctions show at best modest reductions in recidivism and sometimes increase reoffending, while rehabilitation treatments yield consistently positive and relatively large effects. Evidence-based frameworks such as the Risk-Need-Responsivity model, which tailors interventions to an offender’s risk level, criminogenic needs, and learning style, have been shown to reduce recidivism by an average of 17 percent in custodial settings and 35 percent in community settings when all three principles are properly implemented. Research on more than 55,000 prisoners released from Minnesota prisons between 2003 and 2011 found that warehousing inmates without programming increased the odds of recidivism by 13 percent, while participation in effective interventions lowered those odds by 12 to 26 percent.

The authors anticipate an obvious objection: even if punitiveness fails as crime control, punishment serves other purposes. Here they draw on David Garland’s sociology of punishment, which treats punishment as a complex social institution, like the family or the economy, whose meaning cannot be reduced to any single instrumental goal. Populists are entitled, the authors concede, to demand justice and just deserts. But retribution, properly understood, does not license punitiveness. Andrew von Hirsch’s principle of commensurate deserts calls for proportion between the seriousness of a crime and the severity of punishment, and raising penalties for particular offences disrupts the internal ranking of the sentencing scale while overstating an offender’s blameworthiness. As Douglas Husak argues, retribution understood as the infliction of deserved punishment producing intrinsic value can be compatible with a restrictive, even abolitionist, stance toward imprisonment. The populist move from desert to ever-greater severity thus fails on moral as well as empirical grounds.

The democratic claim fares no better. Penal populism presents itself as the voice of the people, but public opinion research suggests that the punitive consensus politicians invoke is largely manufactured. Pierre Bourdieu famously argued that public opinion does not exist in the form its purveyors claim. Julian Roberts and colleagues, drawing on data from five countries, found a wide disjuncture between superficial opinion polls and more sophisticated measures, concluding that support for punitive policies is far less solid than politicians suggest, even though crude polls carry more weight with policymakers. Katherine Beckett’s research showed that public concern about crime and drugs is strongly associated with prior political initiative on those issues, indicating that concern is often politically fabricated rather than spontaneously held. Moreover, when members of the public are given information about the consequences of punitive policies, their support for punitiveness tends to decline, and surveys consistently show public support for rehabilitation alongside other goals of punishment.

The authors are careful to acknowledge context. Criminology itself bears some responsibility for the populist backlash. Robert Martinson’s famous 1974 claim that nothing works in rehabilitation eroded public trust in expert-led penal policy, and although Martinson later retracted much of his conclusion, the damage contributed to what Garland calls the culture of control, in which states abandoned the rehabilitative ideal for risk management and punitive display. Garland has since asked whether criminologists are doing enough to communicate their knowledge credibly, warning that failing to do so leaves the way open for dangerous populist alternatives. The authors also note that a level of genuine public punitiveness exists and is substantial; their point is that opinions formed in the absence of crucial information about consequences are difficult to justify as a basis for policy.

The study’s central contribution is diagnostic rather than prescriptive. By integrating criminology, restrained retributivism, the sociology of punishment, and public opinion research, Bourekkadi and Elarraj demonstrate that penal populism invokes criminology, morality, and democracy selectively yet satisfies none of them. Its policies appeal to emotion while maintaining a veneer of legitimacy through claims of effectiveness and popular support that do not hold. The authors do not argue that punitive policies can never be defended, only that the usual justifications offered for them cannot survive scrutiny, and they hypothesise that reframing the debate around the genuine justification of punishment would drain much of the emotional appeal politicians exploit. Future research, they argue, should develop an alternative framework for penal policy, one grounded in evidence-based practice, proportionality, and democratic integrity, while addressing the structural conditions that allow populist penal policies to persist despite the fallacy of their claims.

Subject of Research: The justificatory failure of penal populism in contemporary criminal justice policy

Article Title: Penal Populism and the Failure of Its Core Claims

Article References: Bourekkadi, O., & Elarraj, N. (2026). Penal Populism and the Failure of Its Core Claims. Discover Global Society, 4(1), Article 252. https://doi.org/10.1007/s44282-026-00588-z

Image Credits: AI Generated

DOI: 10.1007/s44282-026-00588-z

Keywords: penal populism, criminology, criminal justice, deterrence, rehabilitation, retribution, public opinion, punishment, evidence-based policy, populism, sentencing, sociology of punishment

In a new article published in Federal Sentencing Reporter, Jonathan P. Caulkins of Carnegie Mellon University and colleagues examine two recurring problems. The first is the mismatch between how much drug weight a defendant possessed and how central they were to the supply chain. The second is whether sentencing tables treat different drugs with similar harm equivalence, even when their social and physiological impacts differ.

The authors propose a culpability-based theory for sanctioning participants in illicit drug markets. Instead of treating quantity as a dominant proxy for wrongdoing, their framework links recommended sentences to the role an offender played in facilitating access to drugs—particularly the degree to which they helped others obtain harmful substances.

A central technical proposal is to replace the current single quantity table logic with a three-table structure. One table would be used when a defendant’s organizational role cannot be reliably established, producing intermediate guideline ranges. Two additional tables would separate defendants whose roles suggest higher or lower culpability, including those who owned drugs or held key positions versus individuals with minor or irregular participation.

To avoid over-penalizing low-level involvement, the model assigns shorter sentences for minor roles such as couriers, especially when employment resembles piece-rate or gig-like arrangements. The goal is not to abandon guideline structure, but to redirect scarce prison capacity toward higher-impact actors.

The researchers also argue that drug weighting should reflect harm potential rather than conventional categories alone. They outline an alternative approach for psychostimulants—such as methamphetamine and cocaine—and opioids—such as fentanyl and heroin—by focusing on harms associated with each drug type.

Quantity measurement, they add, should be improved. One suggestion imputes drug weight from cash on hand at the time of arrest. This aims to reduce arbitrary sentencing shifts caused by arrest timing—for example, punishing a person less for having fewer remaining drugs after a sale, even if they are otherwise comparable.

Overall, the authors contend that combining role-sensitive tables with more robust harm-based drug comparisons and refined quantity estimation could enable substantial guideline revision while maintaining the system’s basic architecture.

Subject of Research: Federal drug sentencing guidelines; drug policy; culpability-based sentencing; harm-based drug equivalence
Article Title: Revising Federal Drug Sentencing Guidelines to Better Match Sanctions to Harms Available to Purchase
News Publication Date: 19-May-2026
Web References: http://dx.doi.org/10.1215/10539867-12442726
References: Federal Sentencing Reporter; DOI: 10.1215/10539867-12442726
Image Credits: Not provided in the provided content.

Keywords: U.S. Sentencing Guidelines; drug sentencing; culpability; harm-based sentencing; methamphetamine; cocaine; fentanyl; heroin; sentencing reform; federal sentencing policy