The Electoral Sources of Party Unity. A Quantitative Text-Based Analysis on Vote Explanations in the German Bundestag

This Paper aims to understand whether German legislators use their right to submit vote explanations to voice concern with the position of their party for electoral reasons. The paper frames the research question asked in light of theories on the assumed behavioral effects of the nominal vote and of electoral insecurity that results from marginality, party fragmentation, and also intra-party competition. It hypothesizes that nominally elected legislators, and especially legislators that face high electoral insecurity, are more inclined to issue vote explanations. The Paper empirically test this hypothesis on the basis of a semi-automatic text-based analysis of vote explanations in the 17th Bundestag. This allows to not only gauge whether legislators voice dissent but also why they were doing so. These data are matched with statistical data on the electoral context of legislators and also with individual level data on the biographical background of legislators and their position in the 17th Bundestag. For a subset of 1/3 of the 650 legislators that enter our data set, we are able to match survey data resulting from the 2009 German Candidate Study.