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Modeling Preferences Using Roll Call Votes in Parliamentary Systems

  • Thomas Bräuninger (a1), Jochen Müller (a2) and Christian Stecker (a3)


Models of ideal point estimation usually build on the assumption of spatial preferences. This ignores legislators' non-policy incentives and is thus likely to produce implausible results for many legislatures. We study this problem in parliamentary systems and develop a model of roll call voting that considers both the policy and the non-policy, tactical incentives of legislators. We go on to show how the relative weight of these policy and tactical incentives is influenced by the identity of the mover and characteristics of the motion. Analyses of two data sets of 2174 roll call votes in German state legislatures and 3295 roll call votes in the British House of Commons result in three main findings. First, we show that tactical incentives may be more important than policy incentives, and second, that the importance of tactical incentives varies with the importance of motions. Third, there are interesting twists: backbench private members' bills may reverse tactical incentives whereas proposals from anti-system parties are virtually always rejected by moderate parties, rendering these votes uninformative. Our findings have implications for ideal point estimation in parliamentary systems, as well as for research on separation of power systems.


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Authors' note: Earlier versions of this article were presented at the 2013 annual meeting of the MPSA and the 2014 conference of the EPSA. We would like to thank our panelists, Nicholas Allen, Daina Chiba, Christopher Claassen, Michael Peress, and two anonymous referees for their comments and suggestions. We also thank Masha Haghighat- Kashani and Sebastian Juhl for research assistance. Replication materials are available online as Bräuninger, Müller, and Stecker (2016). Supplementary materials for this article are available on the Political Analysis Web site.



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Ainsley, Caitlin, and Maxwell, Laura. 2012. What can we learn from roll call votes? Strategic signaling incentives and the decision to call roll call votes. Working paper, Emory University.
Aldrich, John H., Montgomery, Jacob M., and Sparks, David B. 2014. Polarization and ideology: Partisan sources of low dimensionality in scaled roll call analyses. Political Analysis 22(4): 435–56.
Andeweg, Rudy B., and Thomassen, Jacques. 2011. Pathways to party unity: Sanctions, loyalty, homogeneity and division of Labour in the Dutch Parliament. Party Politics 17(5): 655–72.
Benedetto, Giacomo, and Hix, Simon. 2007. The rejected, the ejected, and the dejected: Explaining government rebels in the 2001–2005 British House of Commons. Comparative Political Studies 40(7): 755–81.
Benoit, Kenneth, and Laver, Michael. 2006. Party policy in modern democracies. London and New York: Routledge.
Blackburn, R., Ryle, M., Griffith, J. A. G., Kennon, A., and Wheeler-Booth, M. A. J. 2003. Griffith & Ryle on Parliament: Functions, practice and procedures. London: Sweet & Maxwell.
Brader, Ted, Tucker, Joshua A., and Duell, Dominik. 2013. Which parties can lead opinion? Experimental evidence on Partisan cue taking in multiparty democracies. Comparative Political Studies 46(11): 14851517.
Bräuninger, Thomas, and Debus, Marc. 2012. Parteienwettbewerb in den deutschen Bundesländern: Unter Mitarbeit von Jochen Müller. Wiesbaden: VS Verlag.
Bräuninger, Thomas, Müller, Jochen, and Stecker, Chrsitian. 2016. Replication data for: Modeling preferences using roll call votes in parliamentary systems. Havard Dataverse.
Burden, Barry C. 2007. Personal roots of representation. Princeton, NJ: Princeton University Press.
Carey, John M. 2007. Competing principals, political institutions, and party unity in legislative voting. American Journal of Political Science 51(1): 92107.
Carroll, Royce, Lewis, Jeffrey B., Lo, James, Poole, Keith T., and Rosenthal, Howard. 2009. Comparing NOMINATE and IDEAL: Points of difference and Monte Carlo tests. Legislative Studies Quarterly 34(4): 555–91.
Cheibub, José Antônio. 2007. Presidentialism, parliamentarism, and democracy. Cambridge, UK: Cambridge University Press.
Clarke, Kevin A., and Primo, David M. 2007. Modernizing political science: A model-based approach. Perspectives on Politics 5(4): 741753.
Clinton, Joshua D. 2003. Integrating voting theory and roll call analysis: A framework. Political Analysis 11(4): 381–96.
Clinton, Joshua D. 2012. Using roll call estimates to test models of politics. Annual Review of Political Science 15(1): 7999.
Clinton, Joshua D., and Meirowitz, Adam. 2001. Agenda constrained legislator ideal points and the spatial voting model. Political Analysis 9(3): 242–59.
Clinton, Joshua D., and Jackman, Simon. 2009. To simulate or NOMINATE?. Legislative Studies Quarterly 34(4): 593621.
Clinton, Joshua, Jackman, Simon, and Rivers, Douglas. 2004. The statistical analysis of roll call data. American Political Science Review 98(2): 355–70.
Coman, Emanuel Emil. 2012. Legislative behavior in Romania: The effect of the 2008 Romanian electoral reform. Legislative Studies Quarterly 37(2): 199224.
Cowley, Philip. 2002. Revolts and rebellions: Parliamentary voting under Blair. London: Politico's.
Cox, Gary W., and McCubbins, Mathew D. 1993. Legislative leviathan: Party government in the House. Berkeley: University of California Press.
Cox, Gary W., and McCubbins, Mathew D. 2005. Setting the agenda: Responsible party government in the US House of Representatives. Cambridge, UK: Cambridge University Press.
Denwood, Matthew J. 2015. runjags: Interface utilities, model templates, parallel computing methods and additional distributions for MCMC models in JAGS, version 2.0.1-4.
Dewan, Torun, and Spirling, Arthur. 2011. Strategic opposition and government cohesion in Westminster democracies. American Political Science Review 105(2): 337–58.
Diermeier, Daniel, and Feddersen, Timothy J. 1998. Cohesion in legislatures and the vote of confidence procedure. American Political Science Review 92(3): 611–21.
Döring, Herbert. 1995. Time as a scarce resource: Government control of the agenda. In Parliaments and majority rule in Western Europe, ed. Döring, Herbert, 223–46. Frankfurt am Main/Westview: Campus/St. Martin's Press.
Godbout, Jean-Francois, and Høyland, Bjørn. 2011. Legislative voting in the Canadian Parliament. Canadian Journal of Political Science 44(2): 367–88.
Golder, Sona Nadenichek. 2006. Pre-electoral coalition formation in parliamentary democracies. British Journal of Political Science 36(2): 193212.
Green-Pedersen, Christoph. 2010. Bringing parties into parliament: The development of parliamentary activities in Western Europe. Party Politics 16(3): 347–69.
Grofman, Bernard. 2004. Downs and two-party convergence. Annual Review of Political Science 7:2546.
Heller, William B. 2001. Making policy stick: Why the government gets what it wants in multiparty parliaments. American Journal of Political Science 45(4): 780–98.
Hix, Simon, and Noury, Abdul. 2016. Government-opposition or left-right? The institutional determinants of voting in legislatures. Political Science Research and Methods, forthcoming.
Høyland, Bjørn. 2010. Procedural and party effects in European Parliament roll-call votes. European Union Politics 11(4): 597613.
Hug, Simon. 2010. Selection effects in roll call votes. British Journal of Political Science 40(1): 225–35.
Jenkins, Shannon. 2008. Party influence on roll call voting: A view from the U.S. states. State Politics & Policy Quarterly 8(3): 239–62.
Kellermann, Michael. 2012. Estimating ideal points in the British House of Commons using early day motions. American Journal of Political Science 56(3): 757–71.
Krehbiel, Keith. 1993. Where's the party? British Journal of Political Science 23(2): 235–66.
Ladewig, Jeffrey W. 2005. Conditional party government and the homogeneity of constituent interests. Journal of Politics 67(4): 10061029.
Lauderdale, Benjamin E. 2010. Unpredictable voters in ideal point estimation. Political Analysis 18(2): 151–71.
Lewis, Jeffrey B., and Poole, Keith T. 2004. Measuring bias and uncertainty in ideal point estimates via the parametric bootstrap. Political Analysis 12(2): 105–27.
Lijphart, Arend. 1999. Patterns of democracy: Government forms and performance in thirty-six countries. New Haven, CT: Yale University Press.
Lynch, P. 2009. From social democracy back to no ideology? The Scottish National Party and ideological change in a multi-level electoral setting. Regional & Federal Studies 19(4–5): 619–39.
Martin, Lanny W., and Vanberg, Georg. 2004. Policing the bargain: Coalition government and parliamentary scrutiny. American Journal of Political Science 48(1): 1327.
Martin, Lanny W., and Vanberg, Georg. 2011. Parliaments and coalitions: The role of legislative institutions in multiparty governance. Oxford: Oxford University Press.
Martin, Lanny W., and Stevenson, Randolph T. 2001. Government formation in parliamentary democracies. American Journal of Political Science 45(1): 3350.
Massetti, Emanuele. 2010. Political strategy and ideological adaptation in regionalist parties in Western Europe: A comparative study of the Northern League, Plaid Cymru, the South Tyrolese People's Party and the Scottish National Party. Doctoral thesis (DPhil), University of Sussex.
May, Thomas Erskine. 2004. Erskine May's treatise on the law, privileges, proceedings and usage of parliament, 23rd ed. London: LexisNexis.
McCarty, Nolan. 2011. Measuring legislative preferences. In The Oxford handbook of the American Congress, eds. Schickler, Eric and Lee, Frances E., 6694. Oxford: Oxford University Press.
McCarty, Nolan, Poole, Keith T., and Rosenthal, Howard. 2001. The hunt for party discipline in Congress. American Political Science Review 95:674–88.
Meguid, Bonnie M. 2005. Competition between unequals: The role of mainstream party strategy in niche party success. American Political Science Review 99(3): 347–59.
Müller, Wolfgang C., and Strøm, eds, Kaare. 1999. Policy, office, or votes? How political parties in Western Europe make hard decisions. Cambridge, UK: Cambridge University Press.
Munzert, Simon, Rubba, Peter Meissner, Christian, and Nyhuis, Dominic. 2015. Automated data collection with R: A practical guide to web scraping and text mining. Chichester: Wiley.
Nolan, Deborah, and Temple Lang, Duncan. 2014. XML and web technologies for data sciences with R. Use R! New York: Springer.
Otjes, Simon. 2011. The Fortuyn effect revisited: How did the LPF affect the Dutch parliamentary party system? Acta Politica 46(4): 400–24.
Pedersen, Helene H. 2012. Policy-seeking parties in multiparty systems: Influence or purity? Party Politics 18(3): 297314.
Peress, Michael. 2009. Small chamber ideal point estimation. Political Analysis 17(3): 276–90.
Plummer, Martyn. 2013. JAGS: A program for analysis of Bayesian graphical models using Gibbs sampling. Version 3.4.0.
Poole, Keith, Lewis, James Lo, Jeffrey, and Carroll, Royce. 2011. Scaling roll call votes with W-NOMINATE in R. Journal of Statistical Software 42(14): 121.
Poole, Keith, Lewis, James Lo, Jeffrey, and Carroll, Royce. 2014. oc: OC roll call analysis Software. R package version 0.95.
Poole, Keith T. 2000. Non-parametric unfolding of binary choice data. Political Analysis 8(3): 211–37.
Poole, Keith T 2005. Spatial models of parliamentary voting. Cambridge, UK: Cambridge University Press.
Powell, G. Bingham. 1986. Extremist parties and political turmoil: Two puzzles. American Journal of Political Science 30(2): 357–78.
Priddy, Sarah. 2015. Free votes in the House of Commons since 1997, Number SN04793 in Commons Briefing papers. London: House of Commons Library.
Proksch, Sven-Oliver, and Slapin, Jonathan B. 2012. Institutional foundations of legislative speech. American Journal of Political Science 56(3): 520–37.
R Core Team. 2014. R: A language and environment for statistical computing, version 3.1.2 (2014-10-31). Vienna, Austria: R Foundation for Statistical Computing.
Rogers, Robert, and Walters, Rhodri. 2015. How parliament works, 7th ed. London: Routledge.
Rosas, Guillermo, Shomer, Yael, and Haptonstahl, Stephen R. 2015. No news is news: Non-ignorable non-response in roll-call data analysis. American Journal of Political Science 59(2): 512–28.
Rosenthal, Howard, and Voeten, Erik. 2004. Analyzing roll calls with perfect spatial voting: France 1946–1958. American Journal of Political Science 48(3): 620–32.
Samuels, David, and Soberg Shugart, Matthew. 2010. Presidents, parties, and prime ministers: How the separation of powers affects party organization and behavior. Cambridge, UK: Cambridge University Press.
Snyder, James M., and Groseclose, Tim. 2000. Estimating party influence in congressional roll-call voting. American Journal of Political Science 44(2): 193.
Spirling, A., and McLean, I. 2006. UK OC OK? Interpreting optimal classification scores for the U.K. House of Commons. Political Analysis 15(1): 8596.
Stecker, Christian. 2010. Causes of roll-call votes supply: Evidence from the German Länder. Journal of Legislative Studies 16(4): 438–59.
Stecker, Christian. 2015. How effects on party unity vary across votes. Party Politics 21(5): 791802.
Stoetzer, Lukas F., and Zittlau, Steffen. 2015. Multidimensional spatial voting with non-separable preferences. Political Analysis 23(3): 415–28.
Tavits, Margit. 2007. Principle vs. pragmatism: Policy shifts and political competition. American Journal of Political Science 51(1): 151–65.
Volkens, Andrea, Lacewell, Onawa Regel, Sven Schultze, Henrike and Werner, Annika. 2010. The Manifesto Data Collection. Manifesto Project (MRG/CMP/MARPOR). Wissenschaftszentrum Berlin.
Zucco, Cesar Jr., and Lauderdale, Benjamin. 2011. Distinguishing between influences on Brazilian legislative behavior. Legislative Studies Quarterly 36(3): 363–96.
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