PETER FLORA is Professor of Sociology at the University of Mannheim. FRANZ KRAUS is Head of EURODATA Research Archive at the Mannheim Centre for European Social Research. DANIELE CARAMANI received his PhD from the European University Institute in Florence in 1997. He worked from 1996 to 1999 at the EURODATA Research Archive of the Mannheim Centre for European Social Research (MZES). He is currently Professor at the Faculties of Political Science of Florence and Urbino and a Senior Research Fellow at MZES. JORDI MARTI-HENNEBERG is Professor of Human Geography at the University of Lleida, Spain.