ing, to the ethical conduct of research involving human subjects. She has published two books and numerous scholarly articles and chapters in medical journals, interdisciplinary journals, and law journals on the intersection of law, medicine, and public health. In addition, she has collaborated with faculty in the law and medical schools and the College of Arts and Sciences on interdisciplinary research projects. A frequent teacher and public speaker on medical ethics and other issues, she is currently developing the Law Emphasis Program in the Vanderbilt University Medical School. In addition to teaching in Vanderbilt University’s law and medical schools, she is a practicing pediatrician at Vanderbilt Medical Center. Clayton is a member of the IOM and previously served on the IOM Committee on Assessing Interactions Among Social, Behavioral, and Genetic Factors in Health and the IOM Board on Health Sciences Policy; she currently chairs the IOM Committee on a Comprehensive Review of the DHHS Office of Family Planning Title X Program. She has a J.D. from Yale University and an M.D. from Harvard University.

Greg Duncan is Edwina S. Tarry professor in the School of Education and Social Policy, Institute for Policy Research, and faculty fellow in the Institute for Poverty Research at Northwestern University. His research interests are primarily in longitudinal survey research that examines the nature and consequences of poverty and welfare dynamics; neighborhood effects on the development of children and adolescents and other issues involving welfare reform, income distribution, and its consequences for children and adults; and intergenerational consequences on children and adolescents of life in a family using welfare. His current research include dynamic aspects of the incidence of poverty among children and other population groups, the heterogeneous mixture of short- and long-term poverty experiences, the apparent vulnerability of a large segment of American society to at least occasional poverty spells, and the concentration of persistent poverty among certain population subgroups, in particular African Americans. He has served on several committees of the National Academies, including the NRC-IOM Committee on Integrating the Science of Early Childhood Development. He was cochair of the NRC-IOM Committee on Evaluation of Children’s Health: Measures of Risks, Protective and Promotional Factors for Assessing Child Health in the Community. He has a Ph.D. in economics from the University of Michigan.

David Harrington is professor of biostatistics in the School of Public Health at Harvard University and chair of the Department of Biostatistics and Computational Biology at the Dana-Farber Cancer Institute. He served as principal investigator of the Statistical Center for the Eastern Cooperative Oncology Group from 1990 to 2000. He conducts research on statisti-