In the last couple days, two new voting studies have come out of France, following the Presidential elections there. One (translation to English) and two (and also in English.) The first included a look at approval voting, and the second score voting, with a range of -2 to 2, and both suggest that France would have gotten a different, and probably better, result if they had used either of these methods. Specifically, the first study found that, if approval voting had been used in the first round, that the two candidates to advance would have been Hollande (the Socialist leader who advanced in the real election, and went on to defeat incumbent center-right President Sarkozy) and the original fourth-place finisher,François Bayrou. Bayrou is an interesting character; he came in third in the previous election, and his Democratic Union party is considered a centrist group. The study also showed that, in a head-to-head match up, Bayrou would have beaten Hollande. This is some real-world data supporting the theory that approval voting does a better job of electing centrist candidates than plurality. They examined instant runoff voting as well, but got the same result as the plurality election, supporting that theory as well.
The second study looked at score voting. Again, Bayrou and Hollande led (and were the only candidates with net-positive scores!) while Sarkozy slipped back to fourth place. Their head-to-head challenges also found Bayrou to be a beats-all winner. They also found very little bullet voting. These studies build on previous, smaller ones from the 2002 and 2007 elections, which found similar results. All told, this is some excellent real-world data adding further evidence to our theoretical expectations of approval and score voting.
Full Article: The Least of All Evils: Two New French Voting Studies.