This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science Magazine, Vol 346, 5 December 2014. Summer Jobs Reduce Violence among Disadvantaged Youth Authors: Sara B. Heller1* Affiliations: 1 University of Pennsylvania and University of Chicago Crime Lab. *Correspondence to: Sara Heller, firstname.lastname@example.org. Abstract: Every day, acts of violence injure over 6,000 people in the U.S. Despite decades of social science arguing that joblessness among disadvantaged youth is a key cause of violent offending, programs to remedy youth unemployment do not consistently reduce delinquency. This study tests whether summer jobs, which shift focus from remediation to prevention, can reduce crime. In a randomized controlled trial among 1,634 disadvantaged high school youth in Chicago, assignment to a summer jobs program decreases violence by 43 percent over 16 months (3.95 fewer violent-crime arrests per 100 youth). The decline occurs largely after the 8-week intervention ends. The results suggest the promise of using low-cost, well-targeted programs to generate meaningful behavioral change, even with a problem as complex as youth violence. One Sentence Summary: A Chicago summer jobs program for disadvantaged high school students reduces youth violence by 43 percent over 16 months.