Lorenzo De Sio, Mark N. Franklin

The Issue Yield model predicts that parties will choose specific issues to emphasise, based on the joint assessment of electoral risks (how divisive is an issue within the party support base) and electoral opportunities (how widely supported is the same issue outside the party). According to this model, issues with high yield are those that combine a high affinity with the existing party base, together with a high potential to reach new voters. In previous work, the model showed a remarkable ability to explain aggregate issue importance as reported by party supporters, as well as issue emphasis in party manifestos. This paper tests the implications at the individual level by comparing a conventional model where issue salience is determined from manifesto data with a revised model where issue salience is determined by issue yield. The empirical findings show that issue yield is a more effective criterion than manifesto emphasis for identifying the issues most closely associated with party support in the minds of voters.