Id said:
Range Voting isn't a bad method, and it's very winnable, but let's not get
carried away and say that RV is as good as Condorcet.
Warren replies:
--my earlier post which stimulated this, was merely claiming that, as a
matter of experimental fact, Range Voting produces Condorcet winners more
often than Condorcet methods do. At first this statement seems impossible by
definition, but the reason it is true is I am speaking of a 50-50
honest+strategic voter mix
I reply:
So youre making unjustified assumptions about how people will vote. You
seem to be assuming that people will vote as sincerely in RV as they would
in wv Condorcet. Not a safe assumption.
Warren continues:
, and asking what it the probability the winner is the same as the (honest
voter) Condorcet winner. My computer sims showed that range voting does so
more often than Condorcet methods based on rank-order ballots. Paradoxical
seeming. But true. Since this is an experimental fact, it is indisputable.
I reply:
Its indisputable in the world of your simulation. To claim that its
indisputable outside that world is to assume a lot. Youre assuming that the
premises on which your simulation is based are all correct, including your
assumption that people will vote as honestly in RV as in wv Condorcet.
Always be careful when drawing conclusions about the real world from
simulation results for single-winner methods. With apportionment,
simulations are more reliable, if we know the form of the state-size
frequency density distribution.
Warren said:
Computer simulations. The page discussing this is
http://www.rangevoting.org/StratHonMix.html (Also, same results happen for
other mixes than 50-50...) CAVEAT: I should note that IEVS presently is only
doing rank order ballots, I.e. equalities in rankings were forbidden in
these sims.
I reply:
That invalidates the simulations. Equal ranking is allowed in every
Condorcet proposal that Ive heard of, including all the proposals of wv
Condorcet, such as SSD and BeatpathWinner in particular.
Warren said:
Quite possibly the situation would change in future IEVS versions that will
permit rank-equalities and wv-condorcet methods. I urge EMers to help me
program more such stuff into IEVS. The IEVS source code (which continues to
evolve) is available http://www.rangevoting.org/IEVS/IEVS.c To riposte to
the caveat, I note that there are theoretical reasons why range voting is
highly likely to generate honest-voter-Condorcet winers, when the range
voters are strategic. The theorem is presented at
http://www.rangevoting.org/AppCW.html .
I reply:
Riker showed that, with any method, a sufficiently well-informed
strategic-voting electorate will choose the CW every time. It was referenced
in _Scientific American_, in 76 or 77. Probably July or thereabouts.
Warren said:
I am not sure that Ossipoff was aware of this theorem
I reply:
As I said, its true for all methods.
or that he was aware of my computer-sim results. I want to make it clear I
am not just ranting the counterintuitive claim that range voting is more
likely to generate Condorcet winners than Condorcet methods. I am proving it
via both theorem and computer simulation. (The computer sims are independent
evidence from this theorem since they were not using the kind of strategic
voters in the theorem, at all.) In the model of strategic behavior in this
theorem, range voting with strategic voters generates Condorcet winners 100%
of the time when they exist. Condorcet methods - even wv-condorcet methods
with rank-equalities permitted - presumably do so less than 100% of the
time?
I reply:
Rikers statement applies to wv Condorcet as well as to RV, and to every
method.
What youre missing is that Condorcet wv allows sincere voting much more
than RV does. Thats why my single-winner criteria have always been about
how much a method penalizes sincere voting. Thats the subject of all of my
defensive strategy criteria.
If yes, then range is definitely better than Condorcet methods for the
purpose of generating Condorcet winners; if no, they are the same.
I reply:
You havent proven that RV is equal to or the same as wv Condorcet for
choosing C.W.s.
Its all in the assumptions on which your work is based.
Mike Ossipoff
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