Crime & justice
11findings0stories
The findings
Post-Program Behavioral Persistence vs. IncapacitationIn OSC+, the bulk of the 35% violent crime arrest reduction occurred after the 7-week summer program concluded, persisting for a full year. In NYC SYEP, mortality reductions (18% drop) and incarceration reductions (10% drop) persisted across multiple post-program years.RCTContemporaneous Crime Reduction in At-Risk YouthSYEP participation decreases overall summer arrests by 17% and felony arrests by 23%. Among the at-risk subgroup, participation reduces summer arrests by 2.75 percentage points (a 23% drop, p < 0.10) and total arrests by 34 per 1,000 youth (a 24% drop). Convictions drop by 31% overall and 2.09 percentage points among at-risk youth (p < 0.01).RCTContemporaneous Incapacitation via Program Hours AllocationArrest reductions occur exclusively during the months of July and August when SYEP is actively operating (23% drop in felony arrests and 17% overall reduction), with arrest rates returning to baseline levels immediately in September after the 25-hour work schedules terminate.RCTCrime-Type Heterogeneity in Social InterventionsOSC+ participation decreased violent crime arrests by 35% (6.4 per 100 youth), but increased property crime arrests over two years by 5.8 per 100 youth from a baseline of 12.7 (a 45% increase), while having no statistically significant effect on other nonviolent crimes.RCTCumulative Disadvantage Disruption in Legal SystemsSYEP participation decreases total convictions during the program summer by 31% (0.0752 percentage points, p < 0.05) and reduces misdemeanor convictions among at-risk youth by 1.56 percentage points (a 60% relative reduction on a 2.61% base, p < 0.05).RCTDifferential Elasticity of Felony vs. Misdemeanor OffensesSYEP participation decreases felony arrests during the program summer by 23% (p < 0.05), whereas overall misdemeanor arrest reductions are smaller in relative magnitude (14%) and less statistically precise, indicating higher responsiveness of high-severity criminal actions to structured summer employment.RCTExtensive Margin Dominance in Youth Crime PreventionSYEP participation decreases the probability of any arrest by 0.128 percentage points (a 17% reduction, p < 0.05) and decreases total arrest counts by 0.00122 arrests per youth (a 15% reduction, p < 0.10) on a control mean of 0.0087. The virtually identical relative percentage reductions (17% vs 15%) demonstrate that criminal deterrence operates almost entirely by preventing first-time arrest contact rather than reducing repeat arrests among already-arrested individuals.RCTMedium-Term Criminal Justice Impact Fade-OutPost-program arrest and conviction effects up to five years show no statistically significant impacts for either group. Among at-risk youth, felony arrest reductions show a persistent directional decrease of roughly 10% (-2.60 percentage points at 1 year, -4.51 at 3 years [p < 0.10], -2.81 at 5 years), while low-risk youth yield precisely estimated zeroes (+0.175 percentage points at 5 years, p > 0.10).RCTPeer Group Composition Constraints in Program TargetingWhile 100% of crime reduction cost savings ($652–$1,250 per participant) stem from the 3% at-risk subgroup, universal open-enrollment programs embed at-risk youth in a broader peer group where 97% of participants have no criminal record, preventing adverse peer contagion.Expert TheoryPost-Program Violence Reduction via Workplace Social-Emotional LearningParticipation in One Summer Chicago Plus (OSC+) reduced violent crime arrests one year after random assignment by 6.4 arrests per 100 youth from a baseline of 18.3 arrests per 100 youth (a 35% reduction), with the bulk of the decline occurring after the program ended. OSC+ increased property crime arrests over two years by 5.8 per 100 youth from a baseline of 12.7 (a 45% increase). Estimated social benefits from violence reduction were nearly six times larger than program costs.RCTYouth Employment Program Incarceration and Mortality MitigationParticipation in the New York City Summer Youth Employment Program (SYEP) reduced the probability of serving prison time by 0.10 percentage points (a 10% reduction from a 0.99% baseline incarceration rate, resulting in 112 fewer youth imprisoned). SYEP participation reduced overall mortality by 0.073 percentage points (an 18% reduction from a 0.41% baseline mortality rate, saving 83 lives), with reductions concentrated among young men.RCT