Issue-salience, Issue-divisiveness and Voting Decisions

We present a framework to analyze the relative importance of issues for the electorate. We distinguish two concepts -- issue salience and issue divisiveness -- and present those in the context of the multidimensional spatial model. Issue salience, which is widely studied in empirical and theoretical models, is the weight of one issue over another in a typical voter's utility function. Issue divisiveness is the differentiation between the issues, which depends on the positions or alignments of competing parties and candidates on each issue. We show that empirical research commonly conflates salience and divisiveness, as the regression coefficient in a multiple regression of vote choice on issues reflects both, the weight or salience of each issue and the distinctiveness of the two parties on each issue. We analyze the example of regional elections in the Basque province of Spain to demonstrate the mechanics and value of the approach developed. The politics of this region provide a good instance where debate over the importance of ideology and nationalism conflates salience and divisiveness.