1. Negotiations, Organizations and Markets Unit, Harvard Business School, Boston, MA, USA
2. Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA, USA
3. Center for Health Incentives and Behavioral Economics, Leonard Davis Institute of Health Economics, Philadelphia, PA, USA
4. Department of Medicine, Duke University School of Medicine, Durham, NC, USA
5. The Blackstone Group, New York, NY, USA
6. Science Department, Weight Watchers International, New York City, NY, USA
7. Cresencz Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA
8. Department of Social and Decision Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
9. Department of Health Care Management, The Wharton School, Philadelphia, PA, USA
10. Departments of Medicine and Medical Ethics and Health Policy, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA