Hi Mike,
In my simulations MJ and Bucklinesque methods usually show similar strategy
patterns to Approval. (Though so
does Range.)
If there are three candidates, you can rank them A>B>C and get protection for A
from the B preference if you
believe that A's viability depends on A having a top-slot majority. If you
think that A could still win with, say, a
49% plurality, it doesn't make a lot of sense to give a preference to B (unless
B is about as good).
In constructed scenarios it's not hard to imagine situations where this could
be a useful guarantee. You can
easily make a situation where if A only gets 49%, it must be that opposing
candidates and voters made up the rest,
in which case it's safe to give the second preference, because A definitely
lost.
But in real elections I would be concerned by the fact that a narrow majority
can be thwarted just by adding in
a few ballots for non-contenders.
If you go lower in the rankings (e.g. consider safety of 2nd preference from
the specified 3rd preference) I think
the numbers just get more and more unclear as to whether you stand to
gain anything for the risk you definitely
take.
By the way, I agree that AERLO methods probably violate FBC. The effects are
too unpredictable.
Kevin
De : MIKE OSSIPOFF <nkk...@hotmail.com>
À : election-meth...@electorama.com
Envoyé le : Lundi 30 janvier 2012 15h09
Objet : [EM] Majority Judgement
Does anyone here know the strategy of MJ? Does anyone here know what valid
strategic claims can be made for it? How would one maximize one’s utility in an
election with acceptable and completely unacceptable candidates who could win?
How about in an election without completely unacceptable candidates who could
win?
And no, I don't mean refer to a website. The question is do YOU, as an MJ
advocate, know what MJ's strategy is?
Of course, if anyone here advocates MJ, then they, themselves, should know MJ’s
strategy, and its advantages and disadvantages, and be able to state them here.
I’m just guessing, but isn’t MJ’s strategy the same as that of RV? (Maximum
rating for candidates you’d vote for in Approval, and minimum points for
candidates you wouldn’t vote for in Approval).
And surely the u/a strategy of MJ is to max-rate the acceptables and min-rate
the unacceptables.
But of course MJ differs from RV in the following way: In RV, if you rate x
higher than y, you’re reliably, unquestionably, helping x against y. In MJ, of
course that isn’t so. In fact, if you like x and y highly, and at all
similarly, and rate sincerely, then you’re unlikely to help one against the
other, at all.
Another difference is that, in MJ, even if you correctly guess that you’re
raising a candidate’s median, you can’t know by how much.
Suppose x is your favorite. y is almost as good. Say the rating range is 0-100.
You sincerely give 100 to x, and 90 to y.
Say I prefer y to x, and, as do you, I consider their merit about the same. If
I rated sincerely, I’d give y 100 and x 90.
But, unlike you, I don’t vote sincerely. Because x is a rival to y, and maybe
also because I expect you to rate sincerely, I take advantage of your sincerity
by giving y 100, and giving x zero.
Because different people have different favorites and near-favorites, your high
rating of x and y is probably above those candidates’ median ratings. So you’re
raising the medians of both candidates, with no particular reason to believe
that you’re raising one’s median more than that of the other.
In our above-described example, that’s what you’re doing: Raising the medians
of x and y. Probably by about the same amount. I, however, am raising y's
median and lowering x's median. You’re raising my candidate’s median, and I’m
lowering your candidate’s median. You aren’t helping x against y. I’m helping y
against x.
You’ve been had.
At least in RV, you’d have reliably somewhat helped x against y.
There's something familiar about that strategy situation :-) MJ fully has the
co-operation/defection problem.
Discussion of a method’s strategy shouldn’t have to come from someone who
doesn’t advocate that method.
A tip: Don’t have confidence in a method whose advocates evidently don’t know
its strategy.
Another thing: Just as one example, try MJ on the Approval bad-example. What
you thereby find out is that, to be usable, MJ needs bylaws and patches, such
as to make it too wordy and elaborate (and arbitrary?) to be publicly
proposable.
Mike Ossipoff
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