Notes and Comments Party System Volatility in Post-Communist Europe

In their 2014 article in the British Journal of Political Science, Eleanor Neff Powell and Joshua A. Tucker examine the determinants of party system volatility in post-communist Europe. Their central conclusion is that replacement volatility – volatility caused by new party entry and old party exit – is driven by long-term economic performance. This article shows that this conclusion is based entirely on a miscalculation of the long-term economic performance of a single country, Bosnia-Herzegovina. The study’s reanalysis suggests that little is known about what causes party system volatility in post-communist Europe. Given the negative consequences traditionally associated with party system volatility, this area of research cries out for new theoretical development. In their well-cited 2014 article in the British Journal of Political Science, Eleanor Neff Powell and Joshua A. Tucker examine party system volatility in post-communist Europe. Following Birch, they highlight the importance of disaggregating volatility into two components: volatility caused by new party entry and old party exit, and volatility caused by vote switching across existing parties. Whereas Birch refers to these components as ‘replacement volatility’ and ‘electoral volatility’, Powell and Tucker refer to them as ‘Type A Volatility’ and ‘Type B Volatility’. Standard measures of volatility, such as the wellknown Pedersen Index, conflate these different components of volatility. This is problematic if the two components of volatility have different causes and consequences. The extent to which party system volatility is driven by replacement or electoral volatility is likely to vary across different contexts. In particular, one would expect replacement volatility to play a larger role in democratizing countries (where parties form, disappear, split and merge as they adapt to a new electoral and institutional environment) than in established democracies (where the parties’ identities have stabilized). Powell and Tucker provide support for this claim when they show that volatility is primarily driven by replacement volatility in the post-communist countries of Eastern Europe, but by electoral volatility in the established democracies of Western Europe. In this note, we challenge their central claim that replacement volatility in post-communist Europe is driven by long-term economic performance.