On Sun, May 2, 2010 at 8:48 AM, <[email protected]> wrote: > See above. Also, based on this comment I've added three links to this > answer in the FAQ.
Great. > Previously I had presumed that election-method experts would go to the pages > that contain the rigorous descriptions (as above). I had intended the FAQ > for average folks (who run away from mathematics and even too many numbers). Well, being able to find stuff on a website is not necessarily the same skill as election methods knowledge. I hit the "about votefair ranking" link, as I just wanted a description. If you search for web-sites on other methods, they normally give a description of the method on the front page or no more than 1 link away. >> I think this method might be proportional even when electing more than >> 2 candidates. Does it meet Droop proportionality? > > The method does not get repeatedly used the way other methods keep reducing > the weight of each voter's ballot. In what I recommend, all ballots return > to full weight after each two successive candidates are chosen. It only gets Droop proportionality for 2 seats. Effectively, a faction with 1/3 of the vote would be able to get half of the seats, i.e. Party A: 40% Party B: 40% Party C: 30% Party A+B will get all the seats, assuming the supporters vote as a bloc. >> However, if there is a condorcet tie, then S might be one of the >> candidates which defeats W pairwise. > > I'm not sure what you are saying here. I mean if there is a condorcet tie, then the winner might end up with a minority. 7) A>B>C 4) B>C>A 5) C>A>B A vs B: 12 - 4 A vs C: 7 - 9 B vs C: 11 - 5 I think A wins here under Votefair? I created a survey on your site with the above votes: http://www.votefair.org/cgi-bin/votefairgenballot.cgi/votingid=59588-57285-34547 This gives A as the most representative/popular and B as the 2nd most representative. If we remove ballots which vote for A first, we get 4) B>C 5) C>B C become (temporary) runner-up. We then compare A to C Ballots which mark A above C 7) A>B>C Ballots which mark C above A 4) B>C>A 5) C>A>B We now have to de-weight the first group of 7 ballots. However, they represent only 43.75% of the votes. Presumably, this means that they are de-weighted to zero? The other 9 voters would then select C as the 2nd most representative candidate. This is not the result that your site gives. However, maybe your site de-weights the ballots by (Va - 0.5)/Va Va = fraction of the votes held by A's supporters. (0.4375 - 0.5)/0.4375 = -0.1429 This gives: -1) B>C 4) B>C 5) C>B If it considered the -1 as +1, then that is a tie between B and C. I tried with 7) A>B>C 2) B>C>A 5) C>A>B and it still gives B the 2nd place. I think maybe the negative number of causing a problem. Maybe the vote totals are unsigned so -1 is equal to the max possible number of votes? ---- Election-Methods mailing list - see http://electorama.com/em for list info
