[EM] Relevance of Consistency

[MIKE OSSIPOFF]

James--

You said that Consistency isn't relevant to the matter of who wins.
No, Consistency failure doesn't amount to a Supreme Court issue
about who the winner is.

But are you sure that it isn't relevant to anything of interest at
all?

Consistency, like a number of other criteria, is relevant to how
well a voting system reflects the electorate's wishes. Say a candidate
wins in each district. If he wins in each district, there's a
meaningful sense in which he can be called the people's choice in
each district. One hopes that the result, when a set of ballots is
counted, in some way represents what those people want. So then
we count the whole set of ballots systemwide, and that candidate
loses. If there's some way in which the outcome in the districts
can be called the people's choice, representative of what they want,
then how can we say that about the systemwide result? The voting
system has acted inconsistently. That's all the criterion is saying.

It would be one thing if that were unavoidable, but it isn't.
Approval doesn't violate Consistency.

Participation, Regularity & Heritage are more examples of
criteria about kinds of inconsistency, or behavior contrary to
a voter's expressed wishes. Approval complies with all of those
criteria.

Now, if we're talking about which 1-balloting voting system we'd
prefer to enact, if proposal-feasibility weren't a consideration,
Condorcet is my favorite--Ranked-Pairs(wv) or BeatpathWinner/CSSD. But
Condorcet violates Consistency, Participation, Regularity, and
Heritage. But Condorcet offers other criteria compliances that directly
relate to majority rule and the lesser-of-2-evils problem. Violations
of Consistency, Participation, Regularity, and Heritage, while not
making sense, while being inconsistent or unresponsive in some way,
don't cause the kinds of problems voters are bothered with. So, in
a way, then, I agree with you that I wouldn't reject an otherwise
excellent method like Condorcet because of Consistency, Participation,
Regularity & Heritage.

But, unlike Condorcet, IRV, when compared to Approval, offers nothing to 
outweigh its violations
of Consistency, Participation, Regularity, & Heritage. So, though I
prefer Condorcet, there's nothing "inconsistent" when I bring up
IRV's failures of those 4 criteria when comparing IRV to Approval.

Actually, of those 4, I usually just bring up Participation, because
of how its violations obviously involve a voter's ballot changing
the outcome contrary to preferences expressed on that ballot. That's
especially compelling.

But, returning to Consistency and similar criteria, when a voting
system gives results that embarrass the claim that it reflects
public wishes, that's relevant.

Sure Approval isn't perfect. But if experience shows that a rank
method such as Condorcet is too difficult to enact, I hope that you'll
consider Approval as an alternate proposal, because of its many advantages, 
especially for such an elegantly simple and easily
proposed & enacted method.

Mike Ossipoff



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