Elections, Public Opinion and Parties (EPOP) Conference location:Oxford date:7-9 September 2012
In the literature on electoral volatility and party defection, structural elements have been put forward as crucial variables. Especially the party system is suggested to be of importance for understanding differences in levels of volatility between countries. First of all, the electoral system has been shown to have an impact on levels of volatility. In majoritarian and highly disproportional systems, electoral volatility proved to be more pronounced. With regard to the party system two dimensions can be distinguished. First, the number of parties within an electoral system is expected to be related to levels of electoral volatility. It is argued that the more options voters have, the more they will be inclined to switch. Second, the extent to which a party system is polarized matters as well. The more polarized a party system is, the larger ideological distances between parties are. Therefore, switching parties implies a more pronounced ideological shift for a voter and should therefore become less probable. Although these variables have been empirically studied separately, there has not yet been a large comparative investigation including them in one analysis with cross-national data on the individual level. Using the second and third module of the CSES project this paper investigated volatility for 25531 respondents in 32 elections between 2000 and 2010. Using multilevel models that include country level variables while controlling for important individual level characteristics we have an optimal control of the simultaneous effect of these separate variables. Our results show that the effect of individual-level variables such as education and a persons’ satisfaction with democracy remain strong predictors of electoral volatility even in a cross-national analysis. Of the variables on the contextual level proportionality and the number of parties seem to have an effect on switching parties between elections. Volatility is higher in more proportional systems. Furthermore, it seems that the sheer number of parties increases the propensity to change a voters choice regardless of their polarization. This last finding is a refutation of a longstanding claim in the literature that it is the distance between the parties rather than the number that influences volatility. Because we tested three different measures for polarization separately that can be found in the literature, this can be considered a robust finding. We furthermore find a cross-level interaction effect that shows that satisfaction with the way democracy works in a country leads to different odds of switching votes depending on the effective number of parties in that election.