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Dimensions of Politics in the European Parliament


  • Earlier versions of this article were presented at Stanford University, Trinity College Dublin, Amsterdam University, UC Berkeley, UCLA, UC San Diego, and the 2003 conference of the European Consortium for Political Research. We would like to thank Matthew Gabel, Simon Jackman, Simon Hug, Howard Rosenthal, and three anonymous referees for helpful comments.

Simon Hix is professor of European and comparative politics, Department of Government, London School of Economics and Political Science, Houghton Street, London WC2A 2AE, United Kingdom ( Abdul Noury is assistant professor of economics, ECARES, Université Libre de Bruxelles, Avenue F D Roosevelt 50, CP114, 1050 Brussels, Belgium ( Gérard Roland is professor of economics and political science, University of California, Berkeley and CEPR, Department of Economics, 549 Evans Hall # 3880, Berkeley, CA 94720-3880 (


We investigate the dimensionality of politics in the European Parliament by applying a scaling method to all roll-call votes between 1979 and 2001 in the European Parliament. Contrary to most existing studies using these methods, we are able to interpret the substantive content of the observed dimensions using exogenous measures of national party policy positions. We find that the main dimension of politics in the European Union's only elected institution is the classic left-right dimension found in domestic politics. A second dimension is also present, although to a lesser extent, which captures government-opposition conflicts as well as national and European party positions on European integration.