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<br>
Pasting from Mike's page:<br>
<blockquote type="cite">
<p><em>Some definitions useful in subsequent criteria definitions:</em>
</p>
<p>A voter votes X over Y if he votes in a way such that if we count
only his ballot, with all the candidates but X & Y deleted from it,
X wins. </p>
<p>[end of definition] </p>
<p>Voting a preference for X over Y means voting X over Y. If a voter
prefers X to Y, and votes X over Y, then he's voting a sincere
preference. If he prefers X to Y and votes Y over X, he's falsifying a
preference. </p>
<p>A voter votes sincerely if he doesn't falsify a preference, and
doesn't fail to vote a sincere preference that the balloting rules in
use would have allowed him to vote in addition to the preferences that
he actually did vote. </p>
<p>[end of definition] </p>
<h2>Strategy-Free Criterion (SFC): </h2>
<em>Preliminary definition: </em>A "Condorcet winner" (CW) is a
candidate who, when compared separately to each one of the other
candidates, is preferred to that other candidate by more voters than
vice-versa. Note that this is about sincere preference, which may
sometimes be different than actual voting.
<h2>
<p>SFC: </p>
</h2>
<p>If no one falsifies a preference, and there's a CW, and a majority
of all the voters prefer the CW to candidate Y, and vote sincerely,
then Y shouldn't win. </p>
<p>[end of definition] </p>
</blockquote>
<br>
<br>
<br>
Michael Ossipoff wrote:<br>
<blockquote type="cite">Kevin and Chris posted their criteria that they
incorrectly claimed equivalent to SFC.
<br>
<br>
These same alternative "SFCs" have been posted to EM before and
thoroughly discussed before.
<br>
In fact, we've been all over this subject before.
</blockquote>
<br>
So why don't you point us to where in the EM archive we can find this
earlier discussion? Are they in your opinion equivalent for<br>
ranked-ballot methods?<br>
<br>
<blockquote type="cite">Though Chris's and Kevin's criteria clearly are
not equivalent to SFC, maybe someone could write a votes-only cirterion
that is. First of all, what's this obsession about "votes-only"?</blockquote>
Some people worry that criteria that give the appearance that we have
to read voters' minds to see if they are met are not the easiest to
check for.<br>
<br>
<blockquote type="cite">Now, quite aside from that, the efforts to
write a votes-only equivalent criterion seem motivated by a desire to
not say things that happen to be what I want to say. I want SFC to be
about the fact that that majority, because they all prefer the CW to Y,
and because there’s no falsification (on a scale sufficient to change
the outcome), can defeat Y by doing nothing other than voting
sincerely.
<br>
<br>
To say it in a way that doesn’t say that wouldn’t be SFC. If someone
wrote such a criterion, then I’d recognize it as a _test_ for SFC
compliance, but not as SFC. When I say that a method passes or fails
SFC, and someone says “What’s that?”, then I want to tell them the SFC
described in the paragraph before this one, the one that relates to the
CW, no need for other than sincere voting by the majority and
non-falsified voting by everyone else. If I worded it like Kevin or
Chris, it wouldn’t be self-evident why it’s desirable to meet that
criterion.
<br>
<br>
Someone could suggest that I use an alternative as the criterion, and
save my SFC as a justification. No, I want the criterion’s value to be
self-evident.</blockquote>
<br>
Well its value as something distinct from the Condorcet criterion
isn't self-evident to me. If this CW>Y majority can't elect the CW,
why do they necessarily<br>
care if Y is elected or not? <br>
<br>
And the way you've dressed this up, I can't see how it really qualifies
as a "strategy criterion". How are the members of this CW>Y
majority supposed to <br>
know whether or not anyone "falsifies a preference"? And if they do
know what are they supposed to do about it?<br>
<br>
>From Steve Eppley's MAM page:<br>
<br>
<blockquote type="cite"> <a
href="Proof%20MAM%20satisfies%20Minimal%20Defense%20and%20Truncation%20Resistance.htm"><i>truncation
resistance</i></a>: Define the "sincere top set" as the smallest subset
<br>
of alternatives such that, for each alternative in the subset,
say x, and <br>
each alternative outside the subset, say y, the number of
voters who <br>
sincerely prefer x over y exceeds the number who sincerely
prefer y <br>
over x. If no voter votes the reverse of any sincere
preference regarding <br>
any pair of alternatives, and more than half of the voters rank
some x in <br>
the sincere top set over some y outside the sincere top set,
then y must <br>
not be elected. (This is a strengthening of a criterion having
the same name <br>
promoted by Mike Ossipoff, whose weaker version applies only
when <br>
the sincere top set contains only one alternative, a Condorcet
winner.)<br>
</blockquote>
<br>
This makes some sense as a strategy criterion, being about deterring a
faction from truncating against the members of the sincere<br>
Smith set. The "weaker version" ascribed to you seems easier to test
for.<br>
<br>
How does that version differ from your present SFC?<br>
<br>
Chris Benham<br>
<br>
<br>
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