Party novelty and congruence: A new approach to measuring party change and volatility. (November 2019)

• Record Type: Journal Article
• Authors: Sikk, Allan; Köker, Philipp
• Is Part Of: Party politics. Volume 25:Number 6(2019)
• Page Start: 759
• Page End: 770
• Publication Date: 2019-11
• Subjects: electoral coalitions -- new parties -- party change -- splits and mergers -- volatility; Political parties -- Periodicals; Political science -- Periodicals; 324.2
• DOI: 10.1177/1354068817747512
• Languages: English
• ISSNs: 1354-0688

Abstract

We propose a new three-dimensional approach to party newness and an interval index of party congruence/novelty. Building on this, we also propose a split-vote-by-congruence (SBC) approach to electoral volatility that employs the index. Four elections from different countries that exhibited different forms of party change are used to illustrate the approach. The congruence/novelty index corresponds to our qualitative case knowledge, and the SBC approach leads to meaningful volatility scores. Ad hoc coding of parties as new/old or singular successors/predecessors can seriously over- or underestimate volatility that explains divergence among volatility scores in literature. By eliminating the need for dichotomous and often controversial coding decisions, the SBC approach allows for a substantially more reliable calculation of volatility.