Measures matter

Abstract

Abstract This chapter introduces the ‘Electoral Candidates in Central and Eastern Europe’ (ECCEE) data set, and explains how it is used for the study of party and party system evolution in this book. The first part of the chapter discusses the nature of the data set and the methods and methodological innovations used for its analysis. The second part of the chapter outlines the measures of candidate turnover and congruence. It proposes two measures of turnover—weighted candidate novelty (WCN) and weighted candidate dropout (WCD)— that account for candidate prominence. The degree of candidate turnover varies between countries and individual elections but there is little evidence of increased stability since the early 1990s, except for the limited number of continuing parties. The final section discusses candidate congruence—a measure of overlap between candidates running in successive elections for pairs of slates (to use a common term for parties and electoral coalitions in a given election). Candidate congruences between slates reveal intricate details of party continuities and can be used to automatically construct nuanced evolutionary trees of party systems.