The Dynamics of European Party Systems: Changing Patterns of Electoral Volatility

Abstract In recent years it has become increasingly difficult to maintain that the European party systems are stable and that they reflect the societal cleavage structures of the past. One developmental aspect of the party systems is singled out for description and analysis in this paper. It is argued that European party systems in terms of electoral volatility, i.e. rates of net change in the electorates, are drifting away from each other. Some of the party systems which have traditionally been considered volatile, apparently are becoming less so, while some other systems are taking on the character of highly volatile party systems. A simple set of hypotheses, based upon the notion of party space, is proposed in order to account for the variation observed. The data lend support to the hypothesis that electoral volatility is a function of the format of the party system and of short-term changes in that format.