On Mon, Nov 2, 2009 at 4:25 AM, robert bristow-johnson <[email protected]> wrote: > > whose *ballot* gets their vote transferred? it shouldn't matter in which > order the counting is. if my ballot is needed to give the candidate what > he > needs, and your ballot isn't needed, then you got to influence the > election > of your next choice, but i did not. that can't be fair.
There are various ways of handling this. One option is to randomly select ballots equal to the size of the surplus and pass them on. On average, this will tend to give the same result, assuming a reasonably large numberr of votes are cast. If the quota was 20,000 and a candidate received 30,000 votes, then 10,000 ballots would be picked at random. This option is not favoured as it can lead to problems with recounting the votes and can make election verification harder, as it won't give the same result twice. Another option is to down weight the ballots and then pass them all on. In that case, all of the above ballots would have their weight reduced, so that they only count as 1/3 of a vote (the other 2/3 remains with the candidate who was elected). This is a slight complexity when a voter's vote is used to elect more than one candidate. You have to multiply all the weights by each other. For example, if after the transfer, some of those votes go to a candidate who gets 22,000 votes, then they would be down weighted a 2nd time. The new weight would be 1/3*(2/22) = 1/33 of a vote. Effectively, his vote was at 1/3 strength and 20/22 of that vote was consumed electing the 2nd candidate. In both cases, the order of the votes doesn't matter. There is also some more complex method called Meek's method which makes things even fairer. However, that requires a computer to determine the winner. It treates the votes A>B>C>D and B>C>D the same if A is eliminated. ---- Election-Methods mailing list - see http://electorama.com/em for list info
