[EM] Dave: Condorcet
MIKE OSSIPOFF
nkklrp at hotmail.com
Mon Apr 2 12:35:59 PDT 2012
Dave wrote:
With Condorcet I can rank Fine above Soso, so that my ranking can
improve the chance of Fine getting elected, while Soso has a chance if
Fine fails.
[endquote]
No you can't--Not unless Condorcet is enacted. Condorcetists are missing that
little detail.
When you advocate Condorcet, or conduct an enactment initiative,
people will be skeptical, due to its complete novelty and relative complexity.
They'll ask "Why this complicated method instead of a different one?"
More important, they'll express the concern that the proposed new complicated method
could have unintended consequences. Complicated methods can do all sorts of unexpected things,
which we might find out about with sufficiently thorough study. Opponents and media will say
"This proposal needs a lot more study".
I'll comment below on Dave's answers to these statements.
>
> Several problems with Condorcet:
>
> 1. Any method at all more elaborate than Approval, and especially a
> method
> as different and elaborate as Condorcet is going to be much more
> suspect
> than Approval is, to the public. Opponents will be able to say, "We
> don't
> know enough about this voting system. It needs much study." Approval
> is
> unique among voting system reform proposals, in that it's so simple,
> and such
> a small modification of Plurality, that it's easy to show that it's
> an improvement
> on Plurality, and only an improvement. That's much more difficult
> for more
> complicated methods such as Condorcet.
Dave wrote:
Agreed that in many elections many voters would be satisfied with
Approval ability.
[endquote]
It's unquestionably an obvious improvement on Plurality. Many won't agree with
you if you say that about a more complicated method such as Condorcet.
The important difference is that people won't be satisfied that a complicated method
won't just make things worse, in some un-forseen way.
Dave continued:
Conceded that counting is more complex than for Approval, but the
voting is only a bit more complex and the complexity only matters when
the voters wish to use the capability.
[endquote]
I disagree. The complexity will matter, will make all the difference, when you propose
Condorcet.
>
> 2. For a handcount, Condorcet has much more count labor than does
> Approval.
> If there are N candidates, then there are N(N-1)/2 pairs of
> candidates. For each
> voter, a vote is counted among each pair of candidates. Now, in
> Approval, let's
> estimate that, on the average, a voter approves half of the
> candidates. N/2
> approvals to be counted per voter. That means that Condorcet has
> (N-1) times more
> votes to be counted, as compared to Approval. Sure, the Condorcet
> handcount needn't
> take longer, if you hire more counters. But, for one thing, the
> count is equally
> more expensive, whether you hire more counters to work the same
> hours, or the
> same number of counters to work longer. Besides, the more count-work
> there is,
> the more opportunity and risk for count-fraud there is.
I question "handcount" when the labor gets heavy, such as for a
senator or governor. Anyway:
Approval estimates are a bit heavy - even with many candidates, voters
cannot afford to vote for much more than 2 or 3 - voting for more
risks electing those they like less.
[endquote]
Incorrect. If some who might win are unacceptable, and if more than 2 or 3 are acceptable,
then you should vote for more than 2 or 3. You should vote for all of the acceptables.
If there are no unacceptable candidates who could win, and if you have no predictive information
about winnability or expected vote totals or frontrunners, then you should vote for all of the
above-mean candidates, even if there are more than 2 or 3 of them.
If the above 2 paragraphs don't apply, then you should vote for all of the
above-expectation candidates--the candidates who are greater than what you expect
from the election.
One special case of that latter strategy, for example, is: If you know who the 2 frontrunners
will be, then vote for the better one, and for everyone who is better than hir. There might be
more than 2 or 3.
And, when people claim that Condorcet makes strategy or tactical voting unnecessary, that
claim is incorrect: Condorcet retains the co-operation/defection problem that Approval has. In
the Approval bad-example that I've posted, and which we've discussed here, Condorcet exhibits the
problem too.
The problem can be dealt with in Approval. No doubt it can be dealt with in Condorcet too. Just don't
claim that Condorcet doesn't require any strategy.
And that's not counting the burial strategy problem. I'm not saying that the burial problem
puts me off from Condorcet.
But there will be tactical voting in Condorcet due to its FBC failure. Favorite-burial. A kind
of tactical strategy that, quite obviously, can never be needed in Approval.
However the necessary complexity is overstated above. Do need to
count how many votes for each candidate as in Approval. Then what of
the pairs? 00 - nothing if neither voted for. 01 or 10 - just count
the one voted for in the later add. 11, but equal ranked - counting
them both leaves a tie. 11, but unequal rank - adjust the loser while
counting the ballot so that when the count is adjusted for the 11 the
result will be correct. After counting all ballots, add each
candidates vote count to each of that candidate's pairs.
[endquote]
I invite you to explain that to people when you propose Condorcet.
Dave continued:
Looking for winner. Look at any pair - the loser cannot be the CW so,
with luck, N-1 comparisons will delete all the non-CWs. Cycles, etc.
can complicate this a bit, but not enough to expect hundreds of
compares for 20 candidates.
[endquote]
Yes, the labor of a Condorcet count might be somewhat reduced by judicious
choices, as you describe above.
Dave continued:
Agreed that Approval is cheap enough to do for its small value. That
does not stop something of more value being worth considering.
[endquote]
No, but Condorcet's complete novelty and its complexity make its acceptance
and enactment very unlikely during the first half of this century.
Condorcetists agonize about the strategy-need of Approval. I've described
its strategy above in this reply, and have described it in more detail elsewhere.
It isn't as difficult as some seem to think.
Warren Smith has told why Approval will usually elect the sincere CW when
there is one, given a few reasonable assumptions.
Aside from that, Approval obviously elects the candidate to whom the most
voters have given an approval.
In an unacceptable/acceptable election, that's the candidate acceptable to the most people.
Otherwise, if it's 0-info, it's the candidate above-mean for the most people.
Otherwise, it's (as in the above cases too) the candidate who is better than expectation
for the most people.
As said, I've observed someone, in a Condorcet presidential poll, ranking all of the Democrat
candidates above Nader, though she preferred Nader's policy proposals to those of the Democrats.
Favorite-burial under Condorcet will be a fact. People will favorite-bury with Condorcet, but
not with Approval.
Earlier I suggested that Condorcet's alleged benefits won't count for much if it is never
enacted, due to its complexity.
Now I ask what good Condorcet's advantages will do when many voters are burying their
favorites? How much will Condorcet's results mean then?
> One other thing: I used to claim that burial strategy is well-
> deterred in Condorcet.
> But now I admit that I was only considering 3-candidate elections.
> With more candidates
> burial isn't well-deterred. If I can find a candidate who will be
> sufficiently well-beaten,
> then I and my faction can safely make hir soundly pair-beat the
> sincere CW, without risk
> of electing that candidate whom we're ranking over the sincere CW.
Huh? If you do not risk your candidate getting elected you have no
chance of more than annoying the CW.
[endquote]
I'm not saying that the burial-strategist doesn't risk the election of his
own candidate. I'm saying that he doesn't risk the election of the loser whom
he (and the rest of his faction) insincerely rank over the sincere CW.
> ICT has some good protection against burial, because burial can only
> work for a
> candidate who is ranked #1 by more people than anyone else in the
> cycle.
ICT or ITC?
[endquote]
ICT. When I wrote "ITC" that was a typo.
Your zillion titles are beyond understanding.
[endquote]
Kevin Venzke proposed a method which he named "ICA". That stands for "Improved
Condorcet, with Approval".
Chris Benham suggested that if, instead of completing improved Condorcet's by
Approval, we instead do so by electing the most top-ranked member of the cycle, or other
improved Condorcet winner-set, then
the method will pass in the Approval bad example, and will be defection-resistant,
as I've defined that term.
Chris gave that method a rather long name, and a long set of initials. I called
it "ICT", in keeping with Kevin's naming, and for the sake of simplicity.
"Improved Condorcet" refers to a way of avoiding Condorcet's FBC failure.
So ICT meets FBC, and is defection-resistant. It's a quite good method, and it
would be great to have it enacted.
But, as I said, it suffers from Condorcet's problem of complete novelty, and complexity,
and the resulting above-described resulting enactment problem.
And, by the way, Approval doesn't have the complete novelty that I've referred to in this
post. It's a simple, direct and natural improvement on Plurality.
Mike Ossipoff
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