Relevance of Consistency

[MIKE OSSIPOFF]

I'd said:

>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.

Blake replied:

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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