Over the last decade, urban districts across the country have undertaken the redesign of high schools as smaller schools with focused missions. These initiatives have been promoted by several foundations as well as district leaders. Recent studies of these efforts in Chicago and New York City provide the best available evidence to date on the effects of these efforts. The papers in this panel present evidence using a variety of methods to estimate the effects of newly designed or redesigned small high schools on student achievement, high school graduation, and educational costs.