New Coalition Models as Alternatives to CDU-SPD Grand Coalitions on the Subnational Level in Germany

The German party system has experienced considerable changes in the last years, on the federal as well as on the Länder level: A decline of the two larger parties CDU/CSU and SPD, the rise of the smaller parties, and the entrance of new parties into parliament cause a significant increase of party system fragmentation. This trend affects well-established routines of government formation. While in 1990, CDU, CSU or SPD either held absolute majorities or at least could form winning coalitions with their preferred coalition partners FDP or Greens, respectively, in 13 out of 16 states, today this is only the case in four states. In the beginning of the fragmentation process, missing majorities for CDU/CSU-FDP or SPD-Green coalitions have often been solved by forming CDU-SPD grand coalitions, but the rising appearance of this type – often understood as a temporary or emergency solution – can be seen as problematic. Our research therefore looks at factors for success or failure of alternative coalition models. In this paper, we compare structurally similar election results in the German Länder between 1990 and 2017 which either led to CDU-SPD grand coalitions or to new coalition constellations, and identify variables which distinguish these two groups. The results not only help us to understand the conditions under which parties are ready to experiment with new coalition formats, but also give insights in intra-party politics by identifying different played by different party state associations.