[EM] Jameson: Regarding preference criteria

[Jameson Quinn]

The point of those criteria was not to have any merit, it was to show why
preference-applying criteria are silly.

Let's forget about those criteria, because apparently the fact that they
are bad criteria is distracting from the issue here. Here are three
statements of the Condorcet criterion:

1. If there is some candidate X such that for every Y != X, more voters
prefer X to Y than vice versa, and no voter insincerely voted Y over X,
then X must win.
2. If there is some candidate X such that for every Y != X, there are more
ballots that could prefer X to Y (that is, either they explicitly show that
preference or they were unable to express a preference for X over Y without
losing some other preference information) than those which definitely
prefer Y over X, then X must win.
3. If there is some candidate X such that for every Y != X, more ballots
prefer X to Y than vice versa, then X must win.

Plurality passes criterion 3. Any non-full-ranking method, including
Condorcet methods like Schulze, fails criterion 1. Obviously, we should be
using criteria which are like 2. Often, we speak of preferences when
specifying the criteria, as a shorthand for the longer-winded precision as
in criteria 2 above.

Jameson
2011/11/21 MIKE OSSIPOFF <nkklrp at hotmail.com>

>
> Jameson--
>
> I said or implied that your criterion was un-applyable because no one can
> establish
> that someone preferred opppositely to how s/he voted.
>
> I take that back. Your criterion isn't unapplyable for that reason.
>
> After all, the failure-example-writer can say anything s/he wants to about
> any matter
> stipulated in the criterion's premise. As the failure-example-writer, you
> can say:
> "That voter prefers B to A, though voting for A, because I say so."  You,
> after all,
> are the one writing the scenario.
>
> For that reason, every method would fail your criterion
>
>
> ...or would if it were written in a way that said something.
>
> But it isn't.
>
> So, really one can only say that it isn't that you've written a criterion
> that is un-applyable.
> One can only say that you haven't written a criterion, because you haven't
> written something
> that has a meaning.
>
> Why do I say that? What do you mean by "votes for A"? Votes A over B as
> I've defined the term?
> Votes for A when the method is Plurality? (So your criterion applies only
> to Plurality?)
>
> If s/he votes A over B as I define that, then A will probably be elected,
> but not necessarily,
> depending on the method. But of course even the fact that it _could_ elect
> A (and would, with every
> method ever proposed or used), means that every method fails your
> criterion.
>
> Criteria that are necessarily failed by every method aren't at all useful.
>
> Anyway, you didn't say what you meant by "votes for A", and that means
> that you haven't
> really defined your criterion.
>
> I just wanted to tell you some things that are wrong with your criterion.
>
>
> Here are your two "definitions" of your inadequately-defined criterion.
>
> Reductio ad absurdem. One voter, two candidates. Preference-based
> criterion: "If the voter votes for A but actually prefers B, then B should
> win".
>
>
> Preference-mentioning criterion: "Imagine the voter prefers B, but due to
> an epileptic seizure, votes for A. The correct winner in this case would be
> B. Therefore, whenever we see a vote for A, we should elect B."
>
>
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