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Party Policy and Group Affiliation in the European Parliament

  • Gail McElroy and Kenneth Benoit

Systematic empirical research has yet to explain how national parties join political groups in the European Parliament. This article first demonstrates, using original empirical measures from expert surveys of party positions, that EP party groups consist of national parties sharing similar policy positions. Secondly, using Bayesian/MCMC methods, the paper estimates the policy determinants of group affiliation using a (conditional) multinomial logit model to explain that ‘party group’ choice is largely driven by policy congruence. Finally, predictions from the model identify national parties not in their ‘ideally congruent’ EP groups. The findings suggest that the organization of and switching between EP groups is driven mainly by a concern to minimize policy incongruence between national and transnational levels.

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1 Kreppel, Amie and Tsebelis, George, ‘Coalition Formation in the European Parliament’, Comparative Political Studies, 32 (1999), 933966; Hix, Simon, Noury, Abdul and Roland, Gérard, ‘Power to the Parties: Cohesion and Competition in the European Parliament, 1979–2001’, British Journal of Political Science, 35 (2005), 209234.

2 Marsh, Michael, ‘Testing the Second Order Election Model’, British Journal of Political Science, 28 (1998), 591607; Reif, Karlheinz and Schmitt, Hermann, ‘Nine Second Order National Elections: A Conceptual Framework for the Analysis of European Election Results’, European Journal of Political Research, 8 (1980), 344.

3 Scharpf, Fritz, Governing in Europe: Effective and Democratic? (Oxford: Oxford University Press, 1999).

4 For a full listing of which national parties were affiliated with which EP groups in June 2004, see McElroy, Gail and Benoit, Kenneth, ‘Party Groups and Policy Positions in the European Parliament’, Party Politics, 13 (2007), 528.

5 Hix, Simon, Noury, Abdul and Roland, Gérard, Democratic Politics in the European Parliament (Cambridge: Cambridge University Press, 2007).

6 Hix, , Noury, and Roland, , Democratic Politics in the European Parliament; Raunio, Tapio, The European Perspective: Transnational Party Groups in the 1989–1994 European Parliament (Aldershot, Surrey: Ashgate, 1997).

7 McElroy and Benoit, ‘Party Groups and Policy Positions in the European Parliament’. Also see Gabel, Matthew and Hix, Simon, ‘Defining the EU Political Space: An Empirical Study of the European Election Manifestos’, in Gary Marks and Marco Steenbergen, eds, European Integration and Political Conflict (Cambridge: Cambridge University Press, 2004), pp. 93119; Hix, , Noury, and Roland, , ‘Power to the Parties: Cohesion and Competition in the European Parliament, 1979–2001’; Thomassen, Jacques, Noury, Abdul and Voeten, Erik, ‘Political Competition in the European Parliament: Evidence from Roll Call and Survey Analyses’, in Marks and Steenbergen, eds, European Integration and Political Conflict, pp. 141164.

8 On punishment mechanisms, see, for instance, Hix, Simon. ‘Electoral Institutions and Legislative Behavior: Explaining Voting Defection in the European Parliament’, World Politics, 56 (2004), 194223; McElroy, Gail, ‘Committees and Party Cohesion in the European Parliament’, Osterreichische Zeitschrift fuer Politikwissenschaft, 37 (2008), pp. 357374.

9 Hix, , Noury, and Roland, , Democratic Politics in the European Parliament, p. 170.

10 Hix, , Noury, and Roland, , Democratic Politics in the European Parliament. Almost 3 per cent of the time MEPs vote against both their party group and national party.

11 Budge, Ian and Klingemann, Hans-Dieter, ‘Finally! Comparative Over-Time Mapping of Party Policy Movement’, in Ian Budge, Hans-Dieter Klingemann, Andrea Volkens, Judith Bara and Eric Tanenbaum, eds, Mapping Policy Preferences: Estimates for Parties, Electors, and Governments 1945–1998 (Oxford: Oxford University Press, 2001), pp. 1950.

12 Black, Duncan, ‘The Theory of Committees and Elections’ (Cambridge: Cambridge University Press, 1958). For a discussion of membership maintenance in groups, see Johnson, Paul E., ‘Unravelling in Democratically Governed Groups’, Rationality and Society, 2 (1990), 434.

13 Johnson, , ‘Unravelling in Democratically Governed Groups’.

14 Hearl, Derek, ‘Towards a Theory of Party Alignment: A Research Note’, European Journal of Political Research, 9 (1981), 309317.

15 Financial Times, ‘Cameron finds Czech mates for Europe bloc’, 3 June 2006, p. 6.

16 McElroy, Gail and Benoit, Kenneth, ‘Party Group Switching in the European Parliament’, in William Heller and Carol Mershon, Political Parties and Legislative Party Switching (Basingstoke, Berks.: Palgrave Macmillan, 2009), pp. 147172. National parties almost always join EP party groups as a bloc, although some exceptions exist; for instance, French MEPs from Union pour un Mouvement Populaire (UMP) divided between the EPP and UEN in the 1999–2004 Parliament. We return to this case below.

17 Hix, , Noury, and Roland, , Democratic Politics in the European Parliament, p. 497.

18 Klingemann, Hans-Dieter, Hofferbert, Richard L. and Budge, Ian, Parties, Policies, and Democracy (Boulder. Colo.: Westview Press, 1994), p. 24. See also Hix, Simon and Marsh, Michael, ‘Punishment or Protest? Understanding European Parliament Elections’, Journal of Politics, 69 (2007), 495510.

19 Lipset, Seymour M. and Rokkan, Stein, Party Systems and Voter Alignments: Cross National Perspectives (New York: The Free Press, 1967).

20 McElroy and Benoit, ‘Party Groups and Policy Positions in the European Parliament’; Benoit, Kenneth and Laver, Michael, Party Policy in Modern Democracies (London: Routledge, 2006).

21 McElroy, and Benoit, , ‘Party Groups and Policy Positions in the European Parliament’.

22 McElroy, and Benoit, , ‘Party Groups and Policy Positions in the European Parliament’, p. 17.

23 Hix, Simon and Lord, Christopher, Political Parties in the European Union (Basingstoke, Hants.: Macmillan, 1997); Gabel and Hix, ‘Defining the EU Political Space’.

24 The EDD was excluded from the analysis as expert survey data existed at the national level for only three national parties.

25 Green, William, Econometric Analysis (London: Prentice Hall, 2000), p. 858.

26 Daniel, McFadden, ‘Conditional Logit Analysis of Qualitative Choice Behaviour’, in Paul Zarembka, ed., Frontiers in Econometrics (New York: Academic Press, 1974), pp. 105142.

27 Financial Times, ‘Tories seek allies from wilder EU fringe’, 1 February 2006, p. 9.

28 The model in Column 2 was estimated using WinBUGS 1.41. For direct comparison to the maximum likelihood results from Column 1, a second Bayesian model was also fitted using Andrew Martin and Kevin Quinn’s MCMCpack package for R, which yielded nearly equivalent results. Full details including the prior distributions and the likelihood function for the model in Table 4 are provided in the Appendix.

29 See, for example, King, Gary, Tomz, Michael and Wittenberg, Jason, ‘Making the Most of Statistical Analyses: Improving Interpretation and Presentation’, American Journal of Political Science, 44 (2001), 347361.

30 This is based on 95 per cent posterior confidence intervals. The full listing of posterior probabilities for every party in both the predicted and actual party groups, as well as a posterior ratio with confidence intervals, is available from the authors.

* Department of Political Science, Trinity College, Dublin (e-mail: and ). Support for this project was provided by the Institute for International Integration Studies, Trinity College, Dublin, and by the European Commission Fifth Framework (project number SERD-2002-00061) and the Irish Research Council for Humanities and Social Sciences. The authors thank Alex Baturo, Tímea Kacskovics, Marina McGale and Slava Mikhaylov for research assistance and the Trinity College Working Group on Statistical Learning for feedback. Gail McElroy thanks the Robert Schuman Centre at the European University Institute, Florence, where she completed this article while in residence as a Jean Monnet Fellow.

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British Journal of Political Science
  • ISSN: 0007-1234
  • EISSN: 1469-2112
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