The Dimensionality of voting behaviour in two European parliaments

Although parliamentary voting behaviour has been widely studied in the context of the US congress using roll call analysis, knowledge of voting behaviour in the multiparty systems of the European context is limited. With automated content analysis on parliamentary proceedings, we collected all votes cast by parties over the past decades in two West European parliaments - Denmark and the Netherlands. We analyse the dimensional structure of policy behaviour of the Danish and Dutch parties comparatively, using spatial modelling method of multidimensional scaling. In doing so we are able to create a relatively dense series of party positions and of the dimensionality of the political space through time. In the paper we focus on the development of the dimensional structure of the two party systems. Several authors have argued that political arenas in West Europe are structured by two dimensions: a socio-economic left-right dimension and a cultural dimension. While the latter dimension used to be characterized by a secular-religious divide, it is now said to be governed by issues like immigration, asylum, nationalism, European integration and cultural progressiveness. We find, however, that the behaviour of parties in the party systems under study predominately follows the logic of a single dimensional space, in which the ‘new politics’ issues are -in time- integrated. Additionally, the results indicate that the entry of new parties raises the number of dimensions necessary to adequately represent voting behaviour, but that this effect is temporary.