Michael Ossipoff wrote:
Your definition of your criteria system sounds conversational and
inexact. Could you demonstrate why Approval and 0-10 CR fail
Condorcet's Criterion, in your system?
Aside from that, why is it ok to speak of intent, but not preference?
Speaking of preference is an ok alternative, but we don't necessarily
want to worry about what might be 'sincere preferences'
that are voluntarily not voted.
Chris continues:
[after naming a long list of criteria met by Approval]
But it fails Majority Favourite and Majority Loser
Do you mean those criteria with your fictitious rankings?
Yes.
I've never denied that rank methods can add advantages not available
in Approval. I've even said that I myself would prefer a good rank
method for our public elections, though I myself, as a voter, would be
content with Approval. It would be a nice luxury to rank the best
candidates, but I don't really care which one of the best candidates
wins.
That is your individual inclination, one which is very convenient for an
Approval advocate.
I'd said:
Obviously majority rule is violated by an outcome that is contrary
to what a majority have voted that they want. For instance, if a
majority vote B over A, then we can assume that, if A or B wins,
they vote that it be B.
Chris says:
That is reasonable, and granted for the sake of argument. That
implies that you agree with Kevin Venzke that Minimal Defense(MD)
must be met
It does?? I don't agree with Keviln Venzke that Minimal Defense (MD)
must be met.
From Levin's page:
*Minimal Defense*. /(Due to Steve Eppley.)/
/If more than half of the voters rank candidate A above candidate B,
and don't rank candidate B above anyone, then candidate B must be
elected with 0% probability./
Steve Eppley has defined and discussed Minimal Defense here
<http://alumnus.caltech.edu/%7Eseppley/> and here
<http://alumnus.caltech.edu/%7Eseppley/Strategic%20Indifference.htm>.
Satisfaction of this criterion implies compliance with Mike Ossipoff's
/strong defensive strategy criterion/, although the reverse is not
necessarily true. That criterion can be found here
<http://www.barnsdle.demon.co.uk/vote/stfree.html>.
http://nodesiege.tripod.com/elections/
It does?? I don't agree with Keviln Venzke that Minimal Defense (MD)
must be met.
I'd be interested in seeing an example of MD failure that you agree (or
are content) with.
Chris continues:
[Approval] is very vulnerable to disinformation campaigns
That's a vague statement that could be said of many methods, including
some that Chris likes.
My statement lacked details, but that doesn't make it "vague". I've
elaborated this criticism of Approval
a few times before.
Say in the lead-up to the election two candidates have announced that
they will run, and accurate polling
of voters' voting intentions shows A52%, B48%. Say the media hate A, so
others that hate A nominate
a third candidate C who is anathema to A's supporters (or at least some
of them). Then those that hate A
set about giving C a high profile and publishing some fake polls that
suggest that C has some chance to
win. This frightens some of the A supporters into approving B, causing A
to win.
47: A
05: AB (disinformed timid A>B preferrers)
46: B
02: CB
Approval: B53, A52, C2.
What "methods that I like" do you have in mind as being comparably
vulnerable to disinformation campaigns?
Sincere preferences:
40: A
29: BC
31: CB
The C voters vote C & B. The B voters vote only B. B wins by defection.
Chris, can you find a majority who is being robbed of victory here?
No, but if 21 or more of the C voters also defect the sincere BC
majority solid coalition is robbed of victory and
the sincere majority loser wins.
I've repeatedly asked you to show that Approval and CR pass or fail
Condorcet's Critrerion, by your fictitious-ranking approach. You never
did. I asked Chris. He couldn't either.
In your example say the 'intended rankings' are
40: A
29: B>C
31: C>B
On these intended rankings, C is the CW. On arriving at the polling
place we pretend that those who
were intending to rank B>C or C>B are surprised to find that they have
to use 2-slot ballots, so they each
make an arbitrary choice whether to approve (consistent with their
intended rankings) one candidate or two.
This could result in these actual cast approval ballots:
40: A
29: B
10: CB
21: C
Approvals: A40, B39, C31.
A wins, failing Condorcet. (This is the same set of cast ballots as in
the "defection backfires because of too
many defectors" example).
Chris Benham
I
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