I'd said:
Blake replied: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.
The argument seems to be that if X wins a district under method M, than
method M says that X is the choice of the district. It makes sense to
think of districts as having choices, and method M says that it is
candidate X. If X wins in every district, then we can look at X as the
unanimous choice of the districts (according to M), and therefore X
should win (if M is being consistent).
The argument takes the convenient phrasing (that a group chooses a
candidate) and interprets this as if it were literally true that groups
have choices. They don't. Neither do districts. Nor is there really a
people's choice in a district.
I reply:
Sure they made a choice, Blake, via the voting system that they used.
Blake continued:
Some people choose one thing, some
another. Of course, you could define people's choice so that it means
the winner under a particular method.
I reply:
Well, you could define a group's choice as what they've chosen :-)
In fact, that's the accepted definition.
Blake continued:
But that doesn't mean that you
can treat the voters as if they were all just participants in a group
opinion.
I reply:
They were participants in a group choice.
***
If Northern California and Southern California choose the same candidate, and when the ballots are combined for an overal California
count, California chooses a different candidate, that's inconsistent
according to that word's usual definition.
It shows that those 3 choices can't each be said to be the one right choice
for the group making the choice. You can say that there's no such thing
anyway, and I can't prove that Approval's choice is the one right
choice for a particular electorate, because I don't know how you'd
define such a thing.
But the point is that Approval's 3 choices in that situation aren't
inconsistent with there being a right choice for a group of people,
and that can't be said for any rank method except for the abominable
Borda. That's why the criterion is called "Consistency".
***
But this objection is coming from the person who claims that it's
meaningful to speak of an objective best candidate, and a right or
wrong pairwise defeat, without supplying definitions for those
terms that include tests for compliance with the definitions.
Mike Ossipoff
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