[EM] Multiwinner Bucklin - proportional, summable (n^3), monotonic (if fully-enough ranked)

[Jameson Quinn]

2010/3/28 Chris Benham <cbenhamau at yahoo.com.au>

> Jameson Quinn wrote (26 March 2010):
>
> <snip>
> "Right now, I think MCV - that is, two-rank, equality-allowed Bucklin, with
> top-two runoffs if no candidate receives a majority of approvals in those
> two ranks - is my favorite proposal for practical implementation."
> <snip>
>
>
> Jameson,
>
> What does "MCV" stand for?
>

Ooops. I garbled your term, didn't I? It's supposed to be Majority Choice
Approval, not Majority Choice Voting.


> Does "top-two runoffs" mean a second trip to the polls?
>

Yes. I regard this as an advantage. If the situation is divisive enough to
prevent a majority choice in two rounds of approval, then a further period
of campaigning is a healthy thing. It's the only way to guarantee a
majority. (I don't think that mandating full ranking counts as a true
majority).


>
> How are the candidates scored to determine the top two? Is it based on the
> candidates' scores after the second Bucklin round?
>
>
That's the simplest answer, and I'd support it. It's also the best answer
with honest voters.

Actually, the best answer for discouraging strategy is to use the two
first-round winners. That tends to discourage strategic bullet voting, since
expanding your second-round approval can not keep your favorite candidate
from a runoff.

As a compromise between these two, I would run the first-round approval
winner against the second-round winner. If these are the same, it probably
shows that people are voting to narrowly; to discourage this from happening,
in that case you use the two first-round winners.

But these are details. I'd strongly support any of these systems, whichever
one had more support from other activists.


> Chris Benham
>

Jameson Quinn
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