Analysing structures of party preference in electronic voting data

In the 2002 Irish general election, 138,011 voters cast their ballots electronically. Election officials published full sets of electronic ballots, including candidate rankings. This article analyses these unique electronic voting data. The intention is to explore a range of features of Irish voting behaviour and draw more general inferences about the structure of voter preferences. The results reveal that most voters rank very few candidates; that the level of 'pure' party voting is relatively low; that many Irish voters seem in practice to use the single transferable vote electoral system as a form of 'disapproval' voting; and that the pattern of rankings recorded dramatically underlines the traditional 'Fianna Fáil versus the rest' characterization of Irish party politics.