1 Irving B. Harris Graduate School of Public Policy Studies, University of Chicago, 1155 E. 60th Street, Chicago, IL, 60637, USA. t-philipson@uchicago.edu.
2 Innovation Center, Global Health and Value, Pfizer Inc., 500 Arcola Road, Collegeville, PA, 19426, USA.
3 Department of Health Care Policy, Harvard Medical School, Boston, MA, USA.
4 Massachusetts General Hospital, Boston, MA, USA.