Center for the Study of Democracy

An ongoing debate in political science research focuses on the degree to which democratic party systems are stable. One camp of authors argues that political cleavages in party systems endure, and thus party systems themselves show few significant signs of increased instability. Another group of authors argues that since the 1970s, political cleavages have weakened, and accordingly, system stability has decreased. My research continues this debate. I suggest that part of the uncertainty surrounding the direction and magnitude of stability trends results from the contrasting methodologies researchers have employed. I solve this difficulty by replicating the data and methods that Rose and Urwin employed in their 1970 study. By using identical measures of electoral change, I can ensure that any trends I find are not due to measurement artifacts. I compare their results from the period 1945-1970 with a new set of results for the 1970-1995 period for the same countries, extending the analysis far beyond other recent studies of partisan stability.