LU ANN ADAY, PHD, is the Lorne Bain Distinguished Professor in Public Health and Medicine at the University of Texas School of Public Health. She is the author of many books, including Evaluating the Healthcare System: Effectiveness, Efficiency, and Equity (1st ed., 1993; 2nd ed., 1998; 3rd ed., 2004); At Risk in America: The Health and Health Care Needs of Vulnerable Populations in the United States (1st ed., 1993; 2nd ed., 2001); and Reinventing Public Health: Policies and Practices for a Healthy Nation (2005). Dr. Aday is a fellow of AcademyHealth (formerly the Association for Health Services Research) and a member of the Institute of Medicine of the National Academy of Sciences.

LLEWELLYN JOSEPH CORNELIUS, PHD, is Professor of Social Work, University of Maryland at Baltimore, School of Social Work. He is also Associate Director of the Institute for Human Services Policy. He has been a visiting scholar at the University of Ghana-Legon, School of Public Health, Department of Sociology and the University of Texas Health Science Center at Houston, School of Public Health. He also has been a fellow in the U.S. Department of Health and Human Services, Agency for Health Care Policy and Research.