At 06:46 AM 8/13/2009, Brian Olson wrote:
I had been kinda resigned to STV being the state of the art in multiwinner methods, but we seriously ought to be able to do better.
Well, there is reweighted Range Voting, as to a theoretical system. As to one in actual practice, STV is pretty good. Those discontinuities are largely down in the noise, the more winners there are, the less important they are, they mostly affect the last determined winners.
But that assumes full ranking, and Lewis Carroll (Charles Dodgson), writing in 1884, realized that most common voters would really only know who their favorite was. So he hit upon what a number of writers on this list called Candidate Proxy and Warren Smith called Asset Voting. So Dodgson proposed that exhausted votes may be exercised by the favorite on the list. (I'm not sure of exact mechanism, I've never seen a copy of the original paper, only commentary on it.) It's actually better than a mere election method, because we can think of the secret ballot, if secret ballot is used, as creating a college of public electors, known individuals controlling blocks of votes, and that can be a standing college, used for many different purposes, including replacement of vacated seats midterm. The College either meets after the balloting, or electors may recast votes as needed by registering them. It can be used to create a floating-district but still geographically based Assembly, if electors choose to cast their votes in precinct blocks, while another seat may represent scattered votes over the whole jurisdiction.
It can also serve as a standing advisory network, where electors may be approached by voters and pass on filtered requests, instead of the voters trying to deal directly with a holder of a seat.
We mostly think only of elections as a static, one-ballot process, this list has given almost no consideration to multiballot methods. Plurality is damn good if a majority is required, probably better than IRV, and spectacular -- definitely better -- if write-ins are allowed in the runoff. Recent election in Long Beach CA where the incumbent mayor was not allowed by term limit rules to be on the ballot. She ran and got a plurality in the primary, then a plurality in the runoff, (because there was only one name on the runoff, due to the rules, and there was a minor additional runoff candidate. It gets even more efficient if the ballot method is Bucklin in both the primary and runoff, because spoiler effect in a runoff can be avoided (which then allows those runoff votest to be write-ins without spoiler harm). If we require that a "preference" must be significant to be worth considering, Bucklin satisfies *in purpose* Condorcet, and even plurality satisfies Condorcet if the process requires a majority to complete (and there is a Condorcet winner and the number of ballots to reach a majority is not limited, and each ballot is a new one, no eliminations. I.e., standard Robert's Rules of Order elections satisfy the Condorcet criterion! -- in the end, that is, because a majority winner on a plurality ballot satisfies Condorcet.).
Asset is very, very good, because it can create a truly representative assembly without political parties. It's personal representation, chosen freely, very few wasted votes, the only votes wasted are those who are not recast by an intransigent candidate holding them. (I'd probably use the Hare quota and leave that last seat vacant, or give a few candidates observer status in the assembly, or something like that, and there are other solutions. It's really a minor problem compared to the vast gap in representation that currently exists. )
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