http://rangevoting.org/IrvParadoxProbabilities.html
computes the probabilities of a lot of pathologies in IRV3. It is, I believe, the best available such computation. The "total paradox probability" in such elections, i.e. the probability that at least one among the 8 pathologies {Q, R, U, V, W, X, Y, Z} occur in a random election, is found to be 24.59%, 13.98%, and 27.50% in our three different probability models. But if we restrict attention to elections in which the IRV process matters, i.e. in which the IRV and plain-plurality winners differ (i.e. exactly the elections IRV-advocates tend to cite as examples of the "success" of the Instant Runoff Voting process), the total paradox probability becomes stunningly large: 74.10%, 72.61%, and 54.44% For the most part, this was not previously recognized. This goes a long way toward explaining why it has been so incredibly easy for people like me to find pathologies in real-world IRV elections, seemingly most of the time we ever looked at any interesting IRV election for which we could obtain enough data, and seemingly especially in the elections cited by IRV-advocates as "great successes" for IRV. It is reasonable, in the face of such massive and frequently-arising evidence that IRV has (obvious) problems, to promote it, as opposed to some simpler method largely free of such problems? -- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step) and math.temple.edu/~wds/homepage/works.html ---- Election-Methods mailing list - see http://electorama.com/em for list info