His research studies have focused on the economic and policy factors influencing medical treatment decisions and health outcomes; technological change in health care and its consequences for health and medical expenditures; and the relationship between health and economic well-being. He has previously served as a visiting scholar at the American Enterprise Institute; a member of the National Academy of Sciences' National Cancer Policy Board; associate editor of the Journal of Health Economics, and co-principal investigator of the Health and Retirement Study, a longitudinal study of the health and economic well-being of older Americans. During 2001 and 2002 he served in the White House as a senior policy director for health care and related economic issues. He has twice received the Arrow Award for Outstanding Research in Health Economics. He earned his PhD in economics from the Massachusetts Institute of Technology, his MD from the Harvard-MIT Division of Health Sciences and Technology, and completed a residency in internal medicine at Brigham and Women's Hospital.