[Election-Methods] Borda-elimination, a Condorcet method for public elections?

[Ian Fellows]

Markus,

Thank you for your insight. I certainly agree with you that only the best
method should be used, but I would pose to you the question: Why is it that
the best method isn't used?

You and I (though not some others) would agree that the condorcet criterion
is the correct one when determining the outcome of single winner elections,
and yet they are not used in any public election anywhere in the world.
Though the current best methods (Yours, and Ranked Pairs), are relatively
new, Condorcet methods have been around for quite a long time. So the
newness of the methodology can't be the reason. The difficulty in changing
an electoral system once it has been started certainly plays a part, but IRV
seems to be making significant inroads in this area whereas Condorcet
methods are not.

I think the answer lies in looking at the organizations that have adopted
the Schulze method.
http://en.wikipedia.org/wiki/Schulze_method

44 organizations, and almost all of them are technically oriented.

The answer seems to me to be clear, complexity. Though beat-path is the best
methodology, and the one that I would use in any professional organization
that I was a part of, it violates a principle of democracy. For an election
method to be "of the people" the people must be able to understand its
implementation. They must be able to understand why one leader was picked,
and not another, and further, how their ballot played a part in that
decision.

This begs that question of whether there is a Condorcet method simple enough
for everyone to understand, and yet having the greatest number of desirable
properties. Perhaps one answer might be in Borda-elimination methods. They
are the only ones to have ever been used in public elections, and have very
little added complexity when compared to IRV. IRV has had a great deal of
success in being adopted, so we know that voters can handle something as
complex as IRV.

Borda-elimination also stacks up favorably when compared to anything but
ranked pairs and Schulze. The only criteria that it doesn't pass are local
IIa, monotonicity and independence of clones.

non-monotonicity, while weird, doesn't imply that the candidate chosen is in
any way inferior to a candidate chosen under a monotonic rule. I would have
thought that the main reason why you would want a monotonic rule is so that
people would accept it as valid. This does not appear to be an issue as IRV
is non-monotonic, and is well liked. There are some possible issues
regarding additional sussepability to strategy, but I'm not sure how serious
those would be. Also, like all condorcet methods, Borda-elimination is
monotonic if there is a Condorcet winner.

local IIa and independence of clones are not passes, and this is an
inferiority. but at least it passes them when there is a Condorcet winner. I
seriously doubt that clones would be a big problem outside FPP, where
vote-splitting is rampant.

So guess I'd ask if the minor theoretical deficiencies are not made up for
by the additional simplicity in populations that would have difficulty
understanding beat-path? Why do you think that no Condorcet method has been
adopted by any government?


Ian
http://thefell.googlepages.com



-----Original Message-----
From: election-methods-bounces at lists.electorama.com
[mailto:election-methods-bounces at lists.electorama.com]On Behalf Of
Markus Schulze
Sent: Friday, December 21, 2007 1:47 PM
To: election-methods at electorama.com
Subject: Re: [Election-Methods] Borda-elimination, a Condorcet method
for public elections?


Dear Ian Fellows,

the Nanson method and the Baldwin method violate
monotonicity and independence of clones. They also
violate the desideratum that candidates, who are not
in the Smith set, should not have any impact on the
result of the elections.

When you try to get a Condorcet method adopted somewhere,
you will not only be attacked by the FPP supporters and
the IRV supporters. You will also be attacked by the
supporters of all kinds of election methods. Therefore,
it will not be sufficient that you argue that the
proposed method is better than FPP and IRV; you will
rather have to argue that the proposed method is the
best of all methods. Therefore, it is useful to propose
a Condorcet method that satisfies a large number of
criteria.

Furthermore, I don't think that it makes much sense to
try to find a Condorcet method that looks as much as
possible like IRV or as much as possible like Borda.
The best method according to IRV's underlying heuristic
will always be IRV; the best method according to the
underlying heuristic of the Borda method will always
be the Borda method. It makes more sense to propose
a Condorcet method that stands on its own legs.

Markus Schulze



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