CHRISTOPHER WINSHIP is professor of sociology at Harvard University. He was previously at Northwestern University as director of the Program in Mathematical Methods in the Social Sciences, and as chair of the Department of Sociology. He was a founding member of Northwestern’s Department of Statistics and held a courtesy appointment in economics. He also served as director of the Economics Research Center at the National Opinion Research Center at the University of Chicago. He is currently doing research on several topics: the Ten Point Coalition, a group of black ministers who are working with the Boston police to reduce youth violence; statistical models for causal analysis; the effects of education on mental ability; causes of the racial difference in performance in elite colleges and universities; and changes in the racial differential in imprisonment rates over the past 60 years. He is currently a member of the NRC-IOM’s Committee on Adolescent Health and Development. He has a Ph.D. in sociology from Harvard University (1977).