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.

The 2013 Italian general elections produced a largely unexpected and destabilizing outcome. The major surprise came from the Movimento 5 stelle (M5s, Five star movement), a brand new, anti-establishment political force which got more than 25% of the valid votes and turned out to be the largest party list in the domestic arena of the Chamber of deputies. The destabilizing nature of the outcome stemmed from the lack of a real winner which ended up in political stalemate. In fact, the center-left won in the Chamber of deputies, but not in the Senate and could not form a cabinet by itself. In the end, the Partito democratico (Pd, Democratic Party) was left with the only unpalatable option to have to form a ‘grand governing coalition’ with Berlusconi’s Popolo delle libertà (Pdl, People of freedom). Indeed, the widespread expectation was that the center-left would win with a large margin. For a long time before the vote most of the polls had indicated that Bersani’s lead was large enough to make his coalition gain the absolute majority of seats in both chambers either alone or together with the Monti’s coalition. It was not the case. Actually, what really happened in the ballot box on February 24th and 25th is still unclear to some extent. Here we will try to give a brief and preliminary explanation, analyzing the background to the election, the results and the role played by the electoral systems, the aggregate vote shifts between the 2013 and 2008 elections, the geographical distributions of the vote, and, finally, the transformation of the party system.

A.CHIARAMONTE, & D’ALIMONTE, R. D. R. (2006). Proporzionale ma non solo. La riforma della Casa delle libertà. IL MULINO, 56, 34–45.