Charles and Marie Robertson Professor of Public and International Affairs, Emeritus and Professor of Economics and Public Affairs, Emeritus at Princeton University. Honorary Fellow at the University of Edinburgh. He is the author or co-author of 400 scientific publications, primarily in the areas of reproductive health and demographic methodology. His recent research has been focused in four areas: medical abortion via telemedicine, emergency contraception, contraceptive failure, and the cost-effectiveness of contraception. He has actively promoted making emergency contraception more widely available as an important step in helping women reduce their risk of unintended pregnancy; in addition to his research on this topic, he maintains an emergency contraception website (not-2-late.com).