This article provides a detailed set of coding rules for disaggregating electoral volatility into two components: volatility caused by new party entry and old party exit, and volatility caused by vote switching across existing parties. After providing an overview of both types of volatility in post-communist countries, the causes of volatility are analysed using a larger dataset than those used in previous studies. The results are startling: most findings based on elections in post-communist countries included in previous studies disappear. Instead, entry and exit volatility is found to be largely a function of long-term economic recovery, and it becomes clear that very little is known about what causes ‘party switching’ volatility. As a robustness test of this latter result, the authors demonstrate that systematic explanations for party-switching volatility in Western Europe can indeed be found.