1. Professor of Quantitative Methods, Department of Philosophy, Politics and Economics, University Witten/Herdecke , Germany
2. Professor of Applied Methods and Comparative Politics, Hertie School of Governance , Berlin, Germany
3. Assistant Professor of Political Science Research Methods, Institute of Political Science, Chemnitz University of Technology , Chemnitz, Germany
4. Profesor Investigador Titular, División de Estudios Políticos, Centro de Investigación y Docencia Económicas (CIDE) , Mexico City, Mexico ; and Associate Professor (Reader) in Quantitative Political Science, Department of Politics and International Studies, University of Warwick, Coventry, UK