PhD in sociology, 1976; Habilitation in sociology, 1980, University of Zurich. Professor for political science, Stein Rokkan Chair, EUI, Florence, Italy, 2012-. Professor for comparative politics, Institute of Political Science, University of Zurich, 2002-2012. Professor of comparative and Swiss politics, Department of Political Science, University of Geneva, 1988-2002. Professor for collective political behaviour, University of Amsterdam, 1984-1988. Private-docent at the Phil I Faculty, University of Zurich, 1980-1986. Assistant, Department of Conflict Research, University of Zurich, 1979-1984. Lecturer, Institute of Sociology, University of Zurich, 1975-1980