Determining decidability: How issue salience divergence structures party systems and affects citizens

This paper argues that issue salience divergence – the extent to which parties in a party system diverge in their allocation of salience across issues – is a key characteristic of party system decidability. Elections do not only matter in that politicians and parties with different policy positions may come to power. They can also matter if competing elites emphasize different issues. Using data from the MARPOR project and the Comparative Study of Electoral Systems, I demonstrate that voters perceive greater differences between parties when parties propose agendas that diverge with respect to issue salience. Furthermore, I demonstrate that perceptions of differences between parties mediate the effect of issue salience divergence on respondents’ satisfaction with democracy and self-reported voter turnout. These findings indicate that salience-based differentiation influences the quality of party systems alongside the traditional party system characteristics with important implications for public opinion and political behavior.