ABSTRACT
To understand the function of volatility in today’s European democracies, one would need to employ the principal-agent model. Where democracy is exercised in the form of party government, it is especially essential for the electorate to monitor politicians. Electoral volatility may increase the responsiveness of the party system to the electorate and increase the accountability of politicians. Party system instability is persistently higher in the East European democracies than in Western Europe. System transition in Eastern Europe passes through the party system as new parties enter and try out their fortunes in the electoral arena. Political innovation in Western Europe also passes through the party system, as new movements challenge politics as the ordinary games of established parties. However, there are signs of decreasing volatility in the East, whereas volatility is on the rise in several West European democracies. There will be convergence between West and East European democracies, as both will have considerable volatility in the future. This is a positive for democratic vitality in Herbert Tingsten’s conception. The level of party system fractionalisation is already the same over the regions of Europe. The principal-agent model would favour several agents as well as agent switches, i.e. a moderate level of party system instability.
