At 11:54 PM 10/15/2005, Chris Benham wrote: >Abd, >You wrote: > >>Note that if the method allows equal ranking, adding clones does >>not require additional ranks. >How on earth do you work that out? "Require" for what purpose?
If a method does not allow equal ranking, and if full ranking is desired, adding clones adds additional ranks without improving the expected outcome for the voter. I was using "clone" to mean an additional candidate who matches an existing candidate in rank, such that the voter is equally happy (or unhappy) with the outcome if either of them wins. If full ranking is not provided and overvoting is not allowed, clones consume ranking space with no immprovement for the voter. This is a very strong argument for allowing overvoting, it improves ballot efficiency. (Most Condorcet proposals seem to allow overvoting, i.e., ranking candidates identically, equivalent to Approval voting). It's not important if full ranking is provided, but providing full ranking, if the candidate set becomes large is impractical. I've seen it argued here that elections are rare that have *many* candidates on the ballot, but the fact that it can happen means that public election methods must be able to deal with the situation. Practically speaking, there appears to be substantial resistance to election reforms that require *many* ranks. It is one of the obstacles to implementing IRV; so San Francisco only implemented a few ranks. I don't know if they allowed overvoting, but the failed IRV initiative in Washington specifically prohibited it (as I recall, the ballot was considered truncated at the overvoted rank.) >You seem to be assuming that it doesn't matter which member of a set >of clones wins, Yes, for anyone who considers them clones. > which is odd >because it is perfectly possible that the two rival front-runners >are members of the same set of clones. This is different usage of clones, unless I misunderstand: clones in this meaning are those candidates such that every voter ranks them the same relative to every other candidate. So if every voter ranks A>B>D and A>C>D, and there are no other candidates, then A and B are clones. This does not negate voters having preferences within the set B,C. But this is not what I meant by clone. ---- election-methods mailing list - see http://electorama.com/em for list info
