1. Columbia Business School, Columbia University, New York, NY, USA
2. National Bureau of Economic Research, Cambridge, Massachusetts, USA
3. Department of Health Policy, School of Medicine, Stanford University, Stanford, California, USA
4. Institute of Labor Economics (IZA), Bonn, Germany
5. Frank Batten School of Leadership and Public Policy, University of Virginia, Charlottesville, Virginia, USA
6. School of Social Work, Columbia University, New York, NY, USA;
7. Centre for Analysis of Social Exclusion, London School of Economics and Political Science, London, United Kingdom