[EM] Question on RCV/IRV multi-seat method used in Minneapolis

[Abd ul-Rahman Lomax]

At 12:04 PM 9/23/2008, you wrote:
>Do you or does anyone know if this muti-seat IRV method that splits
>votes of voters to their second choice candidates after some winning
>candidates receive the threshold amount of votes, exhibits
>non-monotonicity or not like the normal IRV method does?  If so, is
>there an example posted somewhere?

Imagine a two-winner election using STV. The vote-splitting method 
doesn't matter because a scenario can be constructed where there is 
no vote splitting. If one candidate wins with an exact quota of 
first-place votes, those ballots are set aside and are not counted 
any more, because all those voters got their representative. Now the 
remaining ballots are used to elect a representative for the *rest* 
of the voters.

And this is simply an IRV election. So you can use any IRV 
non-monotonicity example. If I'm correct, votes for the 
already-chosen candidate, found on these remaining ballots once 
elimination starts, will be disregarded and the next-lower choice 
awarded the votes, pending victory or elimination.

STV is, as I've said many times, quite a good method, and it gets 
better the more candidates elected, *if* the electorate is 
well-informed and can coherently rank many candidates. Asset Voting 
finesses this problem, by essentially allowing voters to use their 
favorite candidate as a trusted proxy.

Asset has other implications, though. It makes it possible for there 
to be a standing "electoral college," consisting of public voters 
(all those who received votes in the secret ballot portion of the 
election), and this could even become a form of "almost-direct" 
democracy. But it starts as a simple fix for the ballot exhaustion 
problem that plagues IRV and to a lesser extent STV.

The complexities of vote transfers are, in my opinion, justified by 
better representation. Very fair methods exist. I dislike random 
reassignment, but the mathematical methods, simplified to 1/1000 
vote, seem fine to me. What does Cambridge, Massachusetts, do? 
(They've been using STV for a very long time.)

(In Asset Voting, I'd use *exact* quotas, probably the Hare quota, -- 
votes/seats -- and exact fractional transfers, though they would 
presumably be rounded to some reasonable accuracy, sufficient to make 
a change of result from roundoff error very unlikely.)