Warren wrote: > Sorry, my last email was in error: BTR-IRV can entirely eliminate the > Smith set and elect some nonmember.
I don't think it can. BTR-IRV never eliminates a candidate that pairwise beats all the other remaining candidates because such a candidate wouldn't lose the pre-elimination "runoff". So even if all but one of the Smith set had been eliminated, the last member will last until the end and win. So BTR-IRV satisfies Smith, but it does not satisfy Schwartz (at least in my current implementation, where a tied pairwise runoff eliminates each of the two candidates with equal probability). Chris Benham wrote: > As I understand it, BTR-IRV was invented by Rob Le Grand purely as a > gimmick to try to sell Condorcet to IRV supporters. I don't think he > ever seriously suggested it was good, and I don't know how anyone > else got that idea. I did originally suggest it as an IRV-like Condorcet method; I don't claim it to be clearly the best Condorcet method by any means, but I like it as a Condorcet method that seems to encourage strategy less often than some others. Also, given sincere votes, it scores higher on social utility in my simulations than the two other IRV-like Condorcet methods I include: "eliminate the candidate with the fewest first-place votes until a Condorcet candidate among the remaining candidate emerges" and "choose the Condorcet winner if one exists and the IRV winner otherwise". That said, I would not choose to have it (or any other purely ranked-ballot method) used in public elections. -- Rob LeGrand, psephologist [EMAIL PROTECTED] Citizens for Approval Voting http://www.approvalvoting.org/ __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ---- election-methods mailing list - see http://electorama.com/em for list info
