Party Families Beyond Left and Right: Contrasting Conceptions of Party Ideology

There are two principal ways in which parties' ideologies are commonly conceptualised: As verbal images of the good society and the principal ways to realise it and as positions on an abstract left-right dimension. The first conception fits well with the notion of historically evolved ideological currents, such as liberalism, conservatism, and socialism, which have found manifestation in the various party families. The second conception fits better with spatial models of party competition, in particular because a unidimensional political space makes equilibria in party competition possible. This poses the question whether these two conceptions are compatible and if not, which fits the reality of party competition better. Can the positions of party families be arranged neatly on a general left-right axis? Are the positions of parties from different families sufficiently distinct to warrant qualitative categories such as "liberal", "conservative", or "socialist"? These questions are difficult to answer because when parties' political positions are measured usually a comprehensive left-right axis is assumed. As a consequence it is possible to test, for example, the unidimensionality of ideological positions based on the popular Manifesto Project RiLe scores. The paper uses a novel method to reconstruct parties' positions from political texts to answer these questions. It shows that a single left-right axis is not sufficient to adequately describe the political distinctions between the various party families that are currently present in European politics. On the other hand, there is a considerable overlap between the party families. This overlap is created to a large degree by the convergence of parties from different party families on matters of economic policy. In particular, it is the family of social democratic parties that assimilates their political positions to those of other parties.