Project News

Prof. Dr. Thomas Saalfeld

Parliamentary Voting Behaviour in the German Bundestag

Parlamentarisches Abstimmungsverhalten im Deutschen Bundestag

PIs: Prof. Dr. Stefanie Bailer (ETH Zürich), Prof. Dr. Thomas Saalfeld (Otto-Friedrich-Universität Bamberg), Dr. Ulrich Sieberer (Universität Konstanz)

Researchers: Dipl.-Pol. Henning Bergmann (Otto-Friedrich-Universität Bamberg), lic. phil. Tamaki Ohmura (ETH Zürich)

Funding period: 01 May 2012 - 30 April 2014

Funding: Fritz Thyssen Stiftung für Wissenschaftsförderung


Project Description:

Existing studies of parliamentary party groups have generated an extensive body of theory and empirical knowledge of parliamentary behaviour and the role of parties within parliamentary systems. In the face of these established theories, however, the field of legislative studies has not produced equivalent empirical studies explaining behaviour at the level of the individual parliamentarian. Specifically, empirical studies that aim to explain toeing or breaking the party groups’ line in legislative votes are still insufficient. For the German case, this shortcoming in the research can primarily be explained by the lack of a comprehensive database on legislative behaviour. While lists of all roll-call votes are a matter of public documentation, a systematic collection of votes incorporating their relevant context factors is not available. This project is developing a database of every voting decision taken by each Member of Parliament in all roll-call votes in the history of the German Bundestag (1949 – 2013) that will enable in-depth analyses of individual level, party group specific and context relevant factors, as well as secure future attention to the research of the Bundestag.

The initial step in this project was to document the actual voting behaviour. In the next step information on each vote, such as the subject, the initiating parties and the outcome of the vote were collected and integrated into the dataset. Similarly, information on each Member of Parliament, such as her mode and margin of victory at the last election, her position within the party group and her level of seniority were added. The database is finalized with the integration of information on context specific factors, such as the government status and the relative majority of parties.

Following the data integration process the project will proceed to its final stage, namely the analysis of individual level, institutional and context specific factors on voting behaviour. At the institutional level it focuses on the effects of the mixed-member proportional electoral system. Specifically it seeks to understand if the mixed-member system leads to voting behaviour comparable to that of pure majoritarian or proportional electoral systems. At the individual level, personal career ambitions and individual political resources are taken into consideration. Finally, context relevant factors can reveal underlying voting explanations such as government – opposition or coalition dynamics.

Additionally we will seek to explain variations in the “supply” of recorded votes, testing a number of basic hypotheses about the strategic use (frequency, issue areas and timing) of recorded votes in the chamber.

The main achievement of this project lies in its systematic integration of explanatory variables on multiple levels, enabling a comprehensive understanding of legislative voting behaviour.


Data can be accessed via Havard Dataverse: Please also note the information on correct citation.

Project-related Publications:

  • Sieberer, Ulrich/Saalfeld, Thomas/Ohmura, Tamaki/Bergmann, Henning/Bailer, Stefanie (2018): Roll-Call Votes in the German Bundestag: A New Dataset, 1949–2013. British Journal of Political Science,
  • Bergmann, Henning/Bailer, Stefanie/Ohmura, Tamaki/Saalfeld, Thomas/Sieberer, Ulrich (2016): Namentliche Abstimmungen im Bundestag 1949-2013: Befunde aus einem neuen Datensatz. Zeitschrift für Parlamentsfragen 47(1): 26-50.
  • Sieberer, Ulrich (2015). "Using MP Statements to Explain Voting Behaviour in the German Bundestag. An Individual-level Test of the Competing Principals Theory." Party Politics 21(2): 284-294.
  • Bailer, Stefanie/Meißner, Peter/Ohmura, Tamaki/Selb, Peter (2013). Seiteneinsteiger im Deutschen Bundestag. Wiesbaden: Springer VS.
  • Ohmura, Tamaki (2013). "When your name is on the list, it is time to Party: The Candidacy Divide in a Mixed-Member Proportional System." Under review for a special issue of Representation: Bernauer, Julian & Daniel Bochsler (Hg.). Strategic Incentives in Unconventional Electoral Systems.
  • Bailer, Stefanie/Meißner, Peter/Ohmura, Tamaki/Selb, Peter (2011). Rekrutierung und Kompetenzen von Bundestagsabgeordneten.Projektbericht, ETH Zürich.
  • Sieberer, Ulrich (2011). "The Institutional Power of Western European Parliaments: A Multidimensional Analysis." West European Politics 34(4): 731-754.
  • Sieberer, Ulrich (2010). "Behavioral Consequences of Mixed Electoral Systems: Deviating Voting Behavior of District and List MPs in the German Bundestag." Electoral Studies 29(3): 484-496.
  • Bailer, Stefanie (2009a). "Cross Pressures and Cohesion in Transnational Party Groups of the European Parliament." In: Daniela Giannetti und Kenneth Benoit (Hrsg.): Intra-Party Politics and Coalition Governments in Parliamentary Democracies, London, Routledge: 189-204.
  • Bailer, Stefanie (2009b). "What Role for the Whips? A Latent Variable Approach to Leadership Effects on Party Group Cohesion in the European Parliament." Journal of Legislative Studies 15(4): 355-378.
  • Sieberer, Ulrich (2006a). "Party Unity in Parliamentary Democracies: A Comparative Analysis." Journal of Legislative Studies 12(2): 150-178.
  • Sieberer, Ulrich (2006b). "Agenda Setting in the German Bundestag. A Weak Government in a Consensus Democracy." German Politics 15(1): 49-72.
  • Saalfeld, Thomas (2005). "Determinanten der Fraktionsdisziplin: Deutschland im internationalen Vergleich." In: Steffen Ganghof und Philip Manow (Hrsg.): Mechanismen der Politik. Strategische Interaktion im Deutschen Regierungssystem. Frankfurt am Main, Campus Verlag: 35-71.
  • Saalfeld, Thomas (1995a). Parteisoldaten und Rebellen. Fraktionen im Deutschen Bundestag 1949-1990. Opladen, Leske + Budrich.
  • Saalfeld, Thomas (1995b). "On Dogs and Whips. Recorded Votes." In: Herbert Döring (Hrsg.): Parliaments and Majority Rule in Western Europe. Frankfurt am Main, Campus Verlag: 528-565.

Conference Presentations:


  • Bergmann, Henning/Saalfeld, Thomas (2015):"A ‘Weapon of the Weak’? The Strategic Use of Recorded Votes in Germany, 1949-2013." 5th Annual EPSA Conference, Vienna, June 25-27. 
  • Ohmura, Tamaki (2015): "Do Women Matter? Female Representation and Policy Outcomes in the German Bundestag."5th Annual EPSA Conference, Vienna, June 25-27. 


  • Bergmann, Henning/Saalfeld, Thomas (2014): “The Strategic Use of Recorded Votes in the German Bundestag, 1949-2013.” Second General Conference of the ECPR Standing Group on Parliaments, Wien, 26.-28. Juni 2014; General Conference of the European Consortium for Political Research (ECPR), Glasgow, 3.-6. September 2014.
  • Ohmura, Tamaki (2014): “Explaining Voting Behaviour in the German Bundestag (1949-2013): Candidacy Strategy and Re-election Certainty in Mixed-Member Systems”. Second General Conference of the ECPR Standing Group on Parliaments, Wien, 26.-28. Juni 2014.
  • Ohmura, Tamaki (2014): “Voting without the Party: Voting Behaviour on Issues of Conscience in the German Bundestag (1949-2014)”. General Conference of the European Consortium for Political Research (ECPR), Glasgow, 3.-6. September 2014.
  • Sieberer, Ulrich (2014): “When do single member districts increase voting dissent under mixed electoral systems? A longitudinal study of voting behavior in the German Bundestag, 1949-2013”. Second General Conference of the ECPR Standing Group on Parliaments, Wien, 26.-28. Juni 2014; Annual Meeting of the American Political Science Association (APSA), Washington D.C., 28.-31. August 2014.


  • Bailer, Stefanie/Ohmura, Tamaki (2013): “Parliamentary Career Stages and their Influence on Legislative Performance.” ECPR Joint Sessions of Workshops “Understanding Parliamentarians: Individual Goals and Behaviour in European Legislatures”, Mainz, 11.-16. März 2013; CIS Parliaments and Parliamentarians Workshop 2013, 16. Mai 2013; European Political Studies Association, Barcelona, 18.-20. Juni 2013, Barcelona; Annual Meeting of the American Political Science Association (APSA), Chicago, 28. August-1. September 2013.


  • Bailer, Stefanie/Meißner, Peter/Ohmura, Tamaki/Selb, Peter (2012): “Pathways into Parliament. Party Animals, Parachutists and other Patterns.” Second Conference of the European Politicial Science Association, Berlin, 21.-24. Juni 2012; Inaugural General Conference of the ECPR Standing Group on Parliaments, Dublin, 24.-27. Juni 2012.


  • Bailer, Stefanie (2011): "Party Group Discipline in Comparison." General Conference of the European Consortium for Political Research (ECPR), Reykjavik, 25.-28. August 2011.
  • Sieberer, Ulrich (2011): "2011, "'I can(not) follow my party because…' Using MP statements to explain party unity and intra-party groups in the German Bundestag". Paper anlässlich des Workshops "Cohesion, Discipline and Partisan Politics in European Legislatures", ECPR Joint Sessions of Workshops, St. Gallen, 12.-17. April 2011.

Further Information: