At 12:17 PM 3/27/2008, Dave Ketchum wrote: >Ok, I give up on poking at this one. > >While the stated votes may be possible, I do not accept them as being of >enough expectability to be useful in comparison among the election systems.
Dave, you've been reading the Election Methods list for quite some time. Election methods are compared on a theoretical basis, all the time, based on constructed scenarios that show *possible* behavior. For an example, it's commonly asserted that Approval Voting fails the Majority Criterion. Why? Well, it is possible that one candidate gets a majority and does not win, because another candidate gets a *larger* majority. Now, how likely is this? Consider a two-party system. It is, by definition, rare that the winner isn't from one of the two major parties. Approval Voting would be introduced into this context because it can allow voters who support a third party candidate to vote, as well, for a major candidate and thus not waste their vote, reducing the "spoiler effect," and possibly vote-splitting effects. In this context, how likely is it that two candidates gain a majority. Imagine that the electorate is, say, 45% D, 45% R, and 10% G. That's a large third party. For two candidates to gain a majority, almost certainly what we'd have to see is a significant number voters voting for both the R and the D. Sure, it will happen, but because there will also be a significant number of G voters who don't vote for either an A or a B, it's quite unlikely that two candidates will gain a majority, and, indeed, it remains quite possible that no candidate will. No voting method can guarantee a majority winner except by forcing voters to make a choice, say on a ranked ballot, as in Australia, where full ranking is required. It was not claimed that this would be a common scenario, only that it was possible, just as it is possible to have more than one candidate gain a majority in Approval, and it is possible for 2/3 of voters to vote *against* a candidate and that candidate wins under IRV. These studies show something about the possible behavior of election systems, and, in fact, Plurality is known to be ridiculously bad; but that is only under relatively rare conditions, in *most* elections plurality works well enough, producing the same result as, say, IRV or other more advanced methods would. It's the exceptions, though, that are worrisome. ---- Election-Methods mailing list - see http://electorama.com/em for list info
