Two Faces of Party Unity: Roll-Call Behavior and Vote Explanations in the German Bundestag

Mandate type, electoral safety, and defections from the party line: The conditional mandate divide in the German Bundestag, 1949–2013

“…While our analysis focused on the effect of electoral system incentives, a brief look at some control variables is interesting to put the electoral system effects into perspective. Consistent with previous findings, we find that MPs holding leadership positions in parliament and in the executive are less likely to defect from the party line (Bauer-Blaschkowski and Mai, 2019; Ohmura, 2014a; Sieberer, 2010; Zittel and Nyhuis, 2019). We also find lower defection by government MPs compared to opposition MPs (see Bauer-Blaschkowski and Mai, 2019; Sieberer, 2010; Zittel and Nyhuis, 2019; for a different finding, see Ohmura, 2014a).…”

“…Consistent with previous findings, we find that MPs holding leadership positions in parliament and in the executive are less likely to defect from the party line (Bauer-Blaschkowski and Mai, 2019; Ohmura, 2014a; Sieberer, 2010; Zittel and Nyhuis, 2019). We also find lower defection by government MPs compared to opposition MPs (see Bauer-Blaschkowski and Mai, 2019; Sieberer, 2010; Zittel and Nyhuis, 2019; for a different finding, see Ohmura, 2014a). The coefficients for model 3 (Table A-4 in the Online Appendix) show that holding an executive office has by far the strongest effect, whereas the effects of government status and parliamentary offices are roughly similar to the effect of being a pure district candidate with a 50–50 chance of reelection.…”

“…One recent study found more defection by district MPs during the period 2005−2009 and has frequently been cited as evidence of a mandate divide in Germany (Sieberer, 2010). While a similar difference was also observed for the period 1990−1994 (Stratmann, 2006), other studies find no systematic differences for the periods 1957−1965 (Dishaw, 1971), 2002−2013 (Ohmura, 2014a), 2009−2013 (Zittel and Nyhuis, 2019), and 2013−2017 (Bauer-Blaschkowski and Mai, 2019) and ascribe the absence of a mandate divide to contamination between the tiers. A few studies even detect a reverse effect with more defection by list MPs for the period 1953−1957 (Dishaw, 1971; Rueckert and Crane, 1962).…”

“…To make optimal use of the information available, we employ disaggregated data on how an individual MP voted on each roll call vote (see Sieberer, 2010 and following this example Bauer-Blaschkowski and Mai, 2019; Ohmura, 2014a). In comparison to more aggregate approaches such as measuring the number of times an MP defects from the party line during a LP (Stratmann, 2006; Zittel and Nyhuis, 2019), this procedure allows us to control for vote-specific characteristics such as policy area, which prove to be important predictors of defection and vary considerably over time.…”

The Legislative Effects of Campaign Personalization An Analysis on the Legislative Behavior of Successful German Constituency Candidates

“…1 of the rules of procedure of the German Bundestag, explanations can be tabled individually after each floor vote in oral or written form. Oral explanations may not exceed 5 minutes and both forms of explanations are included in the official minutes (Becher & Sieberer, 2008;Sieberer, 2010Sieberer, , 2015Zittel & Nyhuis, 2018). Vote explanations are distinct from floor votes in two ways.…”