Half of individuals released from prison in the United States will be re-incarcerated within three years, creating an incarceration cycle that is detrimental to individuals, families, and communities. There is tremendous public interest in ending this cycle, and public policies can help or hinder the reintegration of those released from jail and prison. This review summarizes the existing empirical evidence on how to intervene with existing offenders to reduce criminal behavior and improve social welfare.

In Discrimination and Disparities, Thomas Sowell describes how economists think about the causes of disparities in socioeconomic outcomes. He cautions against government intervention to reduce disparities, noting that such interventions often have unintended consequences. In this review, I discuss the role of economic theory and empirical evidence in helping move society toward more equitable outcomes. I find far more reason to be hopeful about the role of government than Sowell does, but also argue for more experimentation and rigorous evaluation to be sure that our well-intentioned policies have their intended impacts.

Jurisdictions across the United States have adopted “ban the box” (BTB) policies preventing employers from asking about job applicants’ criminal records until late in the hiring process. Their goal is to improve employment outcomes for those with criminal records, with a secondary goal of reducing racial disparities in employment. However, removing criminal history information could increase statistical discrimination against demographic groups that include more ex-offenders. We use variation in the timing of BTB policies to test BTB’s effects on employment. We find that BTB policies decrease the probability of employment by 3.4 percentage points (5.1%) for young, low-skilled black men.

Gun violence is a major problem in the United States, and extensive prior work has shown that higher temperatures increase violent behavior. We consider whether restricting the concealed carry of firearms mitigates or exacerbates the effect of temperature on violence. We use two identification strategies that exploit daily variation in temperature and variation in gun control policies between and within states. We provide evidence that more-prohibitive concealed-carry laws attenuate the temperature-homicide relationship. Our findings are consistent with more-prohibitive policy regimes reducing the lethality of altercations.

Jurisdictions across the United States have adopted “ban the box” (BTB) policies preventing employers from conducting criminal background checks until late in the job application process. Their primary goal is to increase employment for those with criminal records. If individuals with criminal records view these policies as improving their labor market opportunities, they might move to BTB-adopting places in search of employment. In this paper, we consider BTB's effects on the demographic composition of labor markets and the likelihood that residents report recently moving from other labor markets. We find no evidence that BTB affects migration.

Gun violence is an important problem across the United States. However, the impact of government policies on gunfire has been difficult to test due to limited and low-quality data. This paper uses new, more accurate data on gunfire (generated by ShotSpotter audio sensors) to measure the effects of juvenile curfews in Washington, DC. Using variation in the hours of the DC curfew, we find that this policy increases gunfire incidents by 150% during marginal hours. In contrast, voluntarily reported crime measures (such as 911 calls) suggest that the curfew decreases gun violence, likely because of confounding effects on reporting rates.

We exploit daylight saving time (DST) as an exogenous shock to daylight, using both the discontinuous nature of the policy and the 2007 extension of DST, to consider the impact of light on criminal activity. Regression discontinuity estimates show a 7% decrease in robberies following the shift to DST. As expected, effects are largest during the hours directly affected by the shift in daylight. We discuss our findings within the context of criminal decision making and labor supply, and estimate that the 2007 DST extension resulted in $59 million in annual social cost savings from avoided robberies.

Communities across the United States are reconsidering the public safety benefits of prosecuting nonviolent misdemeanor offenses, yet there is little empirical evidence to inform policy in this area. We report the first estimates of the causal effects of misdemeanor prosecution on defendants’ subsequent criminal justice involvement. We leverage the as-if random assignment of nonviolent misdemeanor cases to assistant district attorneys (ADAs) who decide whether a case should be prosecuted in the Suffolk County District Attorney’s Office in Massachusetts. These ADAs vary in the average leniency of their prosecution decisions. We find that for the marginal defendant, nonprosecution of a nonviolent misdemeanor offense leads to a 53% reduction in the likelihood of a new criminal complaint and a 60% reduction in the number of new criminal complaints over the next two years. These local average treatment effects are largest for defendants without prior criminal records, suggesting that averting criminal record acquisition is an important mechanism driving our findings. We also present evidence that a recent policy change in Suffolk County imposing a presumption of nonprosecution for nonviolent misdemeanor offenses had similar beneficial effects, decreasing the likelihood of subsequent criminal justice involvement.