Since the early 1980s much research has been conducted towards developing theoretical explanations for party system change in Western Europe. Transformation processes have been linked to many courses; and given many names, for instance, ‘electoral volatility’ (Pedersen 1983), ‘new value based polarisation’ (Inglehart 1987), ‘realignment/dealignment’ (Dalton, Flanagan and Beck 1984), and ‘competition and identity’ (Bartolini and Mair 1990). On the whole, all these approaches indicate that some basic characteristics of contemporary Western European party systems have changed.