1 Faculty of Arts and Sciences, Harvard University, Cambridge, MA 02138, USA. The Blackstone Group, London W1J 5AL, UK. tjhwang@post.harvard.edu akesselheim@partners.org.
2 Faculty of Arts and Sciences, Harvard University, Cambridge, MA 02138, USA. Radcliffe Institute for Advanced Study, Harvard University, Cambridge, MA 02138, USA.
3 Program On Regulation, Therapeutics, And Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA. tjhwang@post.harvard.edu akesselheim@partners.org.