Pretrial detention is a highly disruptive experience that can undermine both mental health and successful reintegration into society. In partnership with the Swiss Federal Office of Justice and the cantonal Departments of Justice in Zurich and Bern, we conduct a large-scale field experiment across eleven Swiss remand prisons, randomizing over 3,000 inmates to study the causal effects of two interventions. The first intervention, “prison stress management” (PRISMA), is a version of the WHO-developed psychological intervention Problem Management Plus (PM+) adapted to the prison context. As a short and scalable cognitive-behavioral therapy program, it is designed to help inmates manage stress and to promote prosocial behavioral responses. The second intervention proactively connects incoming inmates with social services to help preserve and stabilize their jobs, housing, and close relationships during detention. Drawing on rich administrative prison records, survey data, and external register data from the Federal Statistical Office, we measure outcomes spanning mental health, institutional behavior, and socio-economic reintegration — including employment, social support, education, and housing — as well as recidivism. The project aims to generate rigorous evidence on how detention facilities can be designed to support incarcerated individuals through detention and beyond.

Many eligible households fail to claim means-tested transfers, forgoing substantial income support. We study health insurance subsidies in Switzerland, running randomized controlled trials with the Canton of Zurich’s social insurance office to estimate what drives take-up. Our experiments test how message framing, application modality, and digital versus paper channels affect the application rate of over 600,000 eligible households per wave. A causal forest estimates heterogeneous treatment effects and identifies which households respond to which interventions; we also estimate downstream effects of subsidy receipt on premium defaults and formal debt certificates. The results directly inform how the canton designs its annual outreach mailing.

Switzerland is currently piloting regulated access to cannabis, but decisions about how to design regulation for a legal market are still largely based on intuition rather than evidence. Our project fills this gap with two large-scale randomized controlled trials (RCTs), conducted in the cantons of Zurich and St. Gallen. In both pilot trials, participants are randomly assigned to different groups with varying degrees of access to regulated cannabis, from no legal access to full access with home delivery. This allows us to draw causal conclusions about the effects of legal access on labor market participation, criminality, and educational outcomes, as well as on the underlying mechanisms that drive them, such as cannabis consumption itself.

The St. Gallen trial also includes a sub-study on the willingness-to-pay for different cannabis products, generating evidence that speaks directly to one of the most immediate policy questions in any legalization effort: how to design effective prices and taxation systems for legally accessible cannabis.

Together, these trials aim to show whether the promise of legal cannabis — less black-market activity and lower exposure to harmful consumption — holds up against its risks, giving policymakers a solid empirical basis for designing cannabis regulation grounded in real behavior rather than assumption.

We collaborated with a public prosecution office in Switzerland to examine how hearings during criminal proceedings affect prosecutors’ verdict decisions as well as defendants’ perceptions of the proceedings and their reoffending. Legal theory highlights the right to be heard as fundamental to the rule of law; yet hearings are also time- and resource-intensive, especially for mass crimes. In Switzerland, more than 90% of all criminal proceedings are handled through penal order proceedings, which are usually decided by the prosecutorial office without a judicial trial. In most such proceedings, prosecutors decide on the verdict solely based on police reports, de facto removing the defendant’s right to be heard. To study the causal effect of hearings, we randomly invite defendants for a hearing prior to the prosecutor’s verdict decision. This allows us to identify the causal effects of hearings on sentencing decisions, perceived fairness, and recidivism.

Incarcerated populations have skyrocketed in most parts of the world over the past decades. Worldwide, more than 10 million people are kept in penal institutions, either as pre-trial detainees or after being sentenced. Rigorous scientific evidence on the effects of incarceration is scant. The Justice Study is a randomized controlled trial (RCT) designed to identify the causal effects of incarceration on various dimensions of human life such as health, cognition, labor market and social integration, education, and criminal involvement. The field experiment is built on the U.S. bail system during pretrial detention. We collaborate with undercapitalized bail funds to offer a lottery to just-arrested individuals who would otherwise not be able to post bail themselves. Through the lottery, the bail funds will post bail for some of them, thereby freeing them from pre-trial detention. All other arrestees experience the proceedings as though there had been no study. This methodology will allow the research team to determine the social and economic consequences of incarceration. From a public policy perspective, the results of the complete RCT would contribute to the active debate about whether the criminal justice system exacerbates social and economic inequality and whether this is a necessary price for historically low levels of crime. See the NOMIS Foundation for more information.

Public attitudes toward criminal justice are often shaped by beliefs about prison life that most people have never actually experienced. In collaboration with the Department of Corrections and Rehabilitation of the Canton of Zurich, we conducted a randomized field experiment offering citizens selected by a random lottery the opportunity to spend up to two days incarcerated in a newly built prison. Volunteering participants followed standard procedures closely mirroring a real inmate’s journey from intake to release, including strip searches, confiscation of all belongings, and a strictly regulated daily routine. Our unique setting allows us to identify the causal effect of firsthand incarceration experience on criminal justice preferences. In addition, we elicited subjects’ beliefs about wellbeing in prison and broader trust in the justice system and its procedural fairness. The project aims to shed light on whether and how personal experience — rather than information alone — shapes public preferences for criminal justice policy.