The aim of my study is to contribute to the development of the theory on the development of party systems in Central and Eastern Europe by establishing a clear and comprehensive model of party development. Indeed, new parties, emerging on the Bulgarian party system have often resulted from splits or mergers between well-established, traditional parties. Taking into account the self-identification of new parties and the number of party members and officials who switch to a new party, I argue that the measurement of electoral volatility should take into account these factors in order to present a more accurate picture of the party system in this country.
