Lost children: Issue salience and the inference of policy positions from party family membership

The two concepts of party policy position and party family are core elements of analyzing party systems. The empirical relationship between these two concepts is however an uneasy one. Policy positions can be derived well from their family membership for some parties, but for others the latter is un-informative and sometimes even misleading. In our paper, we inquire into the causes of this (mis-)fit. We argue that family membership, as an historical contingency, derives from a party taking a stand on an issue that is not addressed by the other parties. Consequently, it is not only the position that the party takes on this issue but also the importance it attaches to the underlying policy dimension that define party identity from the point of view of voters. Family membership is thus bound to be informative especially for parties that put high salience on one specific dimension. But the more a party broadens its political platform, i.e. the more dimensions it addresses, the less salient must each individual dimension be. As a consequence, membership of a specific party family will then be less informative with respect to a its actual political profile. We test these hypotheses using the Chapel Hill expert survey data on policy positions and saliences for parties in 28 European democracies in the period 2000-2012, and a set of party family classifications that we compiled from the literature. Factor analysis shows policy salience to be a good means of classifying some parties into categories, and these categories fit family membership as ascribed to them. Policy position however turns out to be either redundant or misleading for classification in a comparative context. These results, though being encouraging for identifying “niche” parties, point towards only very limited use of the concept of party families for separating “mainstream” parties from each other, especially with a view to their political position.