Mark J. Stern is Kenneth L. M. Pray Professor of Social Welfare and History and Co-Director of the Urban Studies Program at the University of Pennsylvania. An historian by training, Stern has taught social welfare policy since 1980. His scholarship covers United States social history, social welfare policy, and the impact of the arts and culture on urban neighborhoods. He is co-author of One Nation Divisible: What America Was and What It Is Becoming (Russell Sage Foundation Press, 2006), which examines the history of social inequality during the 20th century. Stern is co-founder and Principal Investigator of the Social Impact of the Arts Project (SIAP), a policy research group at the University of Pennsylvania's School of Social Policy & Practice. SIAP conducts research on the role of arts and culture in American cities, with a particular interest in strategies for arts-based revitalization.