Donald A. BarrDonald A. Barr, MD, PhD, is professor emeritus at Stanford University in the Department of Pediatrics. He is the author of Health Disparities in the United States: Social Class, Race, Ethnicity, and the Social Determinants of ealth; Introduction to Biosocial Medicine: The Social, Psychological, and Biological Determinants of Human Behavior and Well-Being; and Crossing the American Health Care Chasm: Finding the Path to Bipartisan Collaboration in National Health Care Policy. Read More Read Less