Party Coherence and Polarisation in Multi-Level Systems – Analysing Swiss Parties Based on VAA Data

Party system research often focuses exclusively on party systems on the national level. However, in federal systems there may be additional independent party systems on local or state level, which differ considerably in many aspects from the national system (Grande 2002). To function properly in a multi-level environment parties are required to provide structural integration and to share resources through all federal levels. Furthermore, the parties also must have the ability to formulate and pursue joint political goals and policy positions through all federal levels (Deschouwer 2003). While structural integration and shared resources have been discussed in research quite frequently, the third aspect, formulating and pursuing joint political goals, has been much less addressed in recent research. In our paper we will use VAA data from Switzerland to analyze party coherence on a large number of policy positions on three levels (national, cantonal/state and local). Swiss parties offer a very distinct federal and decentralized organizational structure, what makes Switzerland an interesting case for this line of research. The national party leaderships are lacking a strong control over the cantonal or local sections, which enjoy a large autonomy to adapt the national party’s policy positions in order to fit better to prevailing cantonal or local preferences (Grande 2002, Ladner 2004). Thus, we expect party coherence to decrease from national to cantonal level and from cantonal to local level. Party coherence is closely linked with political polarization. The Swiss national party system is considered as one of the most polarized in Europe (Vatter 2016), but it remains an open question, whether this high political polarization also can be found on the cantonal or even local level. There exists only one study addressing differences among party polarization between the three federal levels in Switzerland (see Ladner 2007). However, this study is based on data, which is 20 to 30 years old and therefore cannot provide meaningful insights into recent developments. Our paper will also address party polarization. We expect to find less polarization on cantonal and local level due to the assumed decreasing party coherence on the lower levels. Less party coherence should lead to less ideological opinions and allow more pragmatic and cross-party policy positions. The Swiss VAA smartvote provides the data on policy preferences for a wide range of issues. Since smartvote has covered already more than 250 elections in Switzerland, we are able to analyze party coherence and polarization on the national level as well as on cantonal and local level. As smartvote is a candidate-based VAA, we will use the answer sets of more than 12,000 candidates to estimate party positions on 20 to 30 policy issues. Whereas previous research mostly relied only on positions on the left-right scale, our data allows us also to include analysis on specific policy issues. In turn, this opens an additional line of new and important questions: For example, whether parties show different levels of coherence and polarization with regard to different issues, or whether coherence is higher for the parties’ core topics?