1. Peter A. Muennig ( ) is an assistant professor of health policy and management at the Mailman School of Public Health, Columbia University, in New York City.
2. Sherry A. Glied is a professor of health policy and management at the Mailman School of Public Health, currently on leave at the Department of Health and Human Services (HHS), where she is assistant secretary for planning and evaluation. This paper was written prior to her appointment at HHS and does not reflect the official views of HHS.