Peter Graeff is Assistant Professor of Sociology in the Department of Social Sciences, Goethe-University Frankfurt am Main. He obtained a Ph.D. from the University of Bonn. His research interests focus on the analysis of negative and positive social capital and freedom. He is also interested in the methodology of measurement and on statistical methods for the analysis of social science data. He has coedited several books and has published in the disciplines major journals including the Journal of Mathematical Sociology, the European Sociological Review, and Quality and Quantity.