IFPP and Schulze comments (re [EM] Craig's posts

Craig Carey research at ijs.co.nz
Wed Sep 12 10:19:46 PDT 2001



I was hoping that Markus would pick up the ball and fix up these
little blunders, But after a wait and a mess up at my list over
negative numbers, I have returned to post some corrective
comments here. The list has changed a lot since the huge man
sized 'roach stopped writing: the person that knew that voters
wanted to be able to vote sincerely. The one that wanted to found
a movement to oppose the CVD.
This is another boring message that probably does not show anything
worth knowing.

I tried to get Markus to correct his own message but that failed so
I rejoined and wrote


Message 8047 of 8048
 >
 >From:  Markus Schulze <schulze at s...>
 >Date:  Fri Sep 7, 2001  11:09 pm
 >Subject:  Re: [EM] Craig's posts
 >
 >
 >Dear Rob,
 >
 >Rob wrote (7 Sep 2001):
 >> I believe it's similar to IRV, except that every candidate with a
 >> lower-than-average first-place vote count is eliminated, so one step
 >> sometimes eliminates more than one candidate.  For example:
 >>
 >> 45:A>B>C
 >> 22:B>C>A
 >> 33:C>B>A
 >>
 >> IRV picks C after eliminating B, but Craig's IFPP eliminates both B
 >> and C in the first step (neither has the quota of 100/3=33.33 votes)
 >> and elects A.  Note that B is the Condorcet winner!  I find IFPP to
 >> be well short of ideal, although Craig claims that it's monotonic at
 >> least.

If you know what the 3 candidate ideal is then you can state it. I
presume you can't state it. Has the list got ANYBODY that can both
post messages and read my quota-13.htm page and somehow, figure out
whether it is the top half of the document or the bottom half, that
contains the steps of the argument that led to the conclusion they
disagree with.

I guess that the big stumbling block that Rob had, was with the two
simple pictures at the http://www.ijs.co..nz/quota-13.htm page


Back to Schulze.

 >Your example also demonstrates that Craig's IFPP violates the majority
 >criterion for solid coalitions,

That is the unamended one that leads Mr Schulze to accuse persons that
read Mr Schulze's definition literally, of arguing "nonsense". Fortunately
we did not get to any arguing on reality, how votes are integral in number,
and how the trascendentals are the next to go after the negative numbers.

Perhaps we could rename the rule to be the "Infinities of halves" rule.

It seems to be a rule that rejects monotonicity, so these arguments could
be done with an improper purpose if anywhere in the message Mr Schulze
suggested that IFPP also ought be monotonic. That a relic left behind by
mathematicians of the last 50 years.

 >   the reversal symmetry criterion and the
 >independence from clones criterion.


Is that thing the same majority criterion for solid coalitions that
was mentioned by Mr Schulze to the Single-Transferable-Vote list?.
Strangely I just proved that it failed the AV method and then
Mr Markus Shulze said that that was "nonsense". So that is an odd thing
to say about a proof. It was a dispute over shifting what could have been
bugs in the rule, into the AV method. I didn't actually show that the
deadweight of 'vote nonnegative' in Markus's rule was a bug. It was not
actually in the specified rule. The rule did not seem to be important.

 >
 >IFPP also violates the participation criterion. If 5 BCA voters hadn't
 >gone to the polls, then C would have been elected. Thus these 5 BCA
 >voters changed the winner from C to A.
 >

Where is the example. And is the number of winners constrained to be
one. The definition of the 'participation criterion' rule is not plain
when the number of winners is not 1. Roughly the axioms required the
compliance with stronger similar better tests.


 >IFPP also violates the consistency criterion.

Although the EM list spent many messages on this rule. it appeared
to not arrive at a conclusion worth being aware of. It is starting
to become clear that Mr Schulze will identify that a method will
fail a list of undefined or inconsistent rules and not note whether
that is in truth significant or not.

 >Example:
 >
 >   Situation 1:
 >
 >      45: A>B>C
 >      35: B>C>A
 >      14: C>B>A
 >       6: C>A>B
 >
 >      The winner is A.
 >
 >   Situation 2:
 >
 >      45: A>B>C
 >      33: B>C>A
 >      22: C>B>A
 >
 >      The winner is A.
 >
 >   Situation 1+2:
 >
 >      90: A>B>C
 >      68: B>C>A
 >      36: C>B>A
 >       6: C>A>B
 >
 >      The winner is B.
 >
 >Craig claims that IFPP was monotonic. But in so far as he hasn't
 >yet defined IFPP for more than 3 candidates, this claim is quite
 >arbitrary.

Surely alleging nonexistence or inconsistency is better than
alleging arbitrariness since compliance of IFPP with that rule is
defined to occur by an axiom.
How did you select the tips of the spear, i.e. the word
"arbitrary"?.

 >
 >Markus Schulze


I regard this EM list as a place where possibly no light may ever
appear. Regarding the rights stuff for the right rules, I would make
the rules be my P2, P3 and P4.



Craig Carey
http://groups.yahoo.com/group/single-transferable-vote






ATTACHMENT A:

/------------------------------------------------------------
At 98.December.08 16:10 +0100 Tuesday, Markus Schulze wrote:
 >Dear Albert,
 >[Albert Langer] wrote (7 Dec 1998):
...
 >> The expected value of the result they got by turning up and voting
 >> in accordance with their preferences would be 1.0 x $9 = $9.
...
 >
 >If you want to propose new criteria, you should do
 >that _explicitly_. You shouldn't change the currently

To Markus: do you use the word explicit when intending to merely
mean'clarity'.

 >used meaning of the criteria _secretly_ and then
 >pretend that all the other people don't really know what
 >these criteria are all about.
 >
 >This would save time and trouble.

Save one of us time and trouble?.

 >
 >Markus Schulze
\------------------------------------------------------------


ATTACHMENT B:

/------------------------------------------------------------
At 01.05.16 08:25 +1200 Wednesday, Craig Carey wrote to the
   Politicians-and-Polytopes list:
 >
 >
 >A message posted recently to the Election Methods list noted that the
 >Alternative Vote had the seemingly undesirable property that was that
 >when two elections with the same winners and the same candidates and
 >with positive votes were combined, then the winner would change.
 >
 >The first message in the thread is listed here:
 >http://groups.yahoo.com/group/election-methods-list/message/7589
 >
...
 >who is
 >being harmed?. ... electorates [are being harmed but not any people?]
...
 >Craig Carey
...
\------------------------------------------------------------



More information about the Election-Methods mailing list