Quel mode de scrutin pour quel « vainqueur » ? Une expérience sur le vote préférentiel transférable

In this paper, we expose the results of a voting experiment realised in 2007, during the French Presidential election. This experiment aimed at confronting the Single Transferable Vote (SVT) procedure to two criteria : simplicity and the selection of a Condorcet-winner. Building on our electoral sample?s preferences, we show that this voting procedure can design a different winner, depending on the vote counting process. With the vote counting process advocated by Hare, the winner is Nicolas Sarkozy, while the Coombs vote counting process has François Bayrou as winner. For these two vote counting processes, the details of the experiment are the same and it is shown that the simplicity criterion is respected. However, with regard to the Condorcet-winner criterion, the Coombs method is the only one to elect the Condorcet-winner, i.e. François Bayrou.