Henry J. Aaronis a senior fellow in Economic Studies at the Brookings Institution, where he holds the Bruce and Virginia MacLaury Chair. Among his many books are Can We Say No? The Challenge of Rationing Health Care, with William B. Schwartz and Melissa Cox (Brookings, 2006), and Reforming Medicare: Options,Tradeoffs, and Opportunities, written with Jeanne Lambrew (Brookings, 2008). William B. Schwartz is an expert on national health policy and is a professor of medicine at the University of Southern California. He was formerly chairman of the Department of Medicine and Vannevar Bush Professor at Tufts University and was also president of the American Society of Nephrology.