Re: [EM] Wikimedia's Board of Trustees elections, 2011

2011-06-21 Thread Markus Schulze

Hallo,

Wikimedia has now published details of
the latest Board of Trustees elections:

http://meta.wikimedia.org/wiki/Board_elections/2011/Results/en

There was a circular tie for positions 7 to 9.

Cain beat Richardson 861:818.
Richardson beat Lorente 838:832.
Lorente beat Cain 789:784.

Markus Schulze


Election-Methods mailing list - see http://electorama.com/em for list info


[EM] Eric Maskin promotes the Black method

2011-06-21 Thread Markus Schulze

Hallo,

Eric Maskin, a Nobel laureate, is currently very
active in promoting the Black method. The Black
method says: If there is a Condorcet winner, then
the Condorcet winner should win; if there is no
Condorcet winner, then the Borda winner should win.

See e.g.:

1 Sep 2009: http://research.microsoft.com/apps/video/default.aspx?id=143268
8 Apr 2011: http://www.youtube.com/watch?v=Bx_lt06W9Ww

Maskin argues as follows:

   If election method X is the best possible
   election method in domain X and if election
   method Y is the best possible election method
   in domain Y and if domain X and domain Y are
   disjoint and if domain X and domain Y together
   cover all possible situations, then the best
   possible election method is to use election
   method X in domain X and election method Y in
   domain Y.

Maskin argues: domain X = situations with a
Condorcet winner; election method X = any
Condorcet method; domain Y = situations
without a Condorcet winner; election method Y
= Borda method.

***

That method, that uses election method X in
domain X and election method Y in domain Y,
will be called election method Z.

***

Maskin's argumentation doesn't work because
of the following reason: Whether an election
method is good or bad depends on which criteria
it satisfies. Most criteria say how the result
should change when the profile changes. Now it
can happen that the original profile and the
new profile are in different domains. This
means that, to satisfy some criterion, election
method X for domain X and election method Y for
domain Y must not be chosen independent from
each other.

Example:

The participation criterion says that adding
some ballots, that rank candidate A above
candidate B, must not change the winner from
candidate A to candidate B.

Election method X satisfies the participation
criterion in domain X. Reason: If candidate A
was the winner in the original profile and if
the original profile was in domain X, then this
means that candidate A was the Condorcet winner
and, therefore, that candidate A pairwise beat
candidate B. If candidate B is the winner in
the new profile and if the new profile is in
domain X, then this means that candidate B
is the Condorcet winner and, therefore, that
candidate B pairwise beats candidate A. If
candidate A pairwise beat candidate B in the
original profile and if candidate B pairwise
beats candidate A in the new profile, then
this means that the added ballots rank
candidate B above candidate A.

Election method Y satisfies the participation
criterion in domain Y, because the Borda method
satisfies the participation criterion in general.

However, election method Z doesn't satisfy the
participation criterion since the Condorcet
criterion and the participation criterion are
incompatible.

In short: Even if election method X satisfies
criterion A in domain X and election method Y
satisfies criterion A in domain Y, it doesn't
mean that election method Z satisfies
criterion A. Therefore, Maskin's argumentation
doesn't work.

***

I also question the claim that the Borda
method is the best possible election method
in situations without a Condorcet winner.

Markus Schulze


Election-Methods mailing list - see http://electorama.com/em for list info


Re: [EM] Eric Maskin promotes the Black method

2011-06-21 Thread Kristofer Munsterhjelm

Markus Schulze wrote:

Hallo,

Eric Maskin, a Nobel laureate, is currently very
active in promoting the Black method. The Black
method says: If there is a Condorcet winner, then
the Condorcet winner should win; if there is no
Condorcet winner, then the Borda winner should win.


(...)


Maskin's argumentation doesn't work because
of the following reason: Whether an election
method is good or bad depends on which criteria
it satisfies. Most criteria say how the result
should change when the profile changes. Now it
can happen that the original profile and the
new profile are in different domains. This
means that, to satisfy some criterion, election
method X for domain X and election method Y for
domain Y must not be chosen independent from
each other.


I find it strange for a Nobel laureate (and within mechanism design at 
that!) to not notice this. I've mentioned my concept of discontinuity 
before, and it seems quite obvious that if you stitch together two 
methods, you can't just look at how one method behaves and how the other 
does, but also the boundary between the two. To my knowledge the 
Participation and LNH incompatibility proofs against Condorcet work this 
way: they show that no matter how you smooth the transition between the 
Condorcet domain and the non-Condorcet domain, there will be sudden 
transitions (discontinuities) and you can't line them all up at the 
same time.


Moreover, I agree with you that Borda doesn't seem to be very good. 
Well, it works when there's no strategy (and it gets respectable regret 
in such cases), but strategy is very obvious and can backfire horribly 
(as by Warren's NEC example where the mediocre candidates win because of 
massive burial).
The burial strategy may be obvious enough that voters would engage in it 
even if they thought there would be a CW. They would think that perhaps 
there won't be a CW and in that case I should maximize the effect of my 
vote, similar to how FPC could encourage compromising in a 
Nader/Bush/Gore scenario.


Finally, if one accepts that the Condorcet criterion makes sense, and to 
comply with it is best when there is a CW, why not expand? Why not limit 
oneself to the Smith set, or to uncovered candidates? The decision to be 
Condorcet compliant but to go no further in the Condorcet direction 
seems rather arbitrary.



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Re: [EM] Eric Maskin promotes the Black method

2011-06-21 Thread Peter Zbornik
Dear all,

Why not write an open letter to him (i.e. publish the letter on this
list) and invite him to further discuss on this list?
I found Maskin's email: mas...@ias.edu in his CV, which is online.
If hybrid methods is the way to go, then the forthcoming paper in
Voting matters which Kristofer linked to seems to be better than his
Condorcet-Borda:
http://www.votingmatters.org.uk/FORTHCOMING/I29P1f.pdf

Peter

On Tue, Jun 21, 2011 at 1:56 PM, Markus Schulze
markus.schu...@alumni.tu-berlin.de wrote:

 Hallo,

 Eric Maskin, a Nobel laureate, is currently very
 active in promoting the Black method. The Black
 method says: If there is a Condorcet winner, then
 the Condorcet winner should win; if there is no
 Condorcet winner, then the Borda winner should win.

 See e.g.:

 1 Sep 2009: http://research.microsoft.com/apps/video/default.aspx?id=143268
 8 Apr 2011: http://www.youtube.com/watch?v=Bx_lt06W9Ww

 Maskin argues as follows:

   If election method X is the best possible
   election method in domain X and if election
   method Y is the best possible election method
   in domain Y and if domain X and domain Y are
   disjoint and if domain X and domain Y together
   cover all possible situations, then the best
   possible election method is to use election
   method X in domain X and election method Y in
   domain Y.

 Maskin argues: domain X = situations with a
 Condorcet winner; election method X = any
 Condorcet method; domain Y = situations
 without a Condorcet winner; election method Y
 = Borda method.

 ***

 That method, that uses election method X in
 domain X and election method Y in domain Y,
 will be called election method Z.

 ***

 Maskin's argumentation doesn't work because
 of the following reason: Whether an election
 method is good or bad depends on which criteria
 it satisfies. Most criteria say how the result
 should change when the profile changes. Now it
 can happen that the original profile and the
 new profile are in different domains. This
 means that, to satisfy some criterion, election
 method X for domain X and election method Y for
 domain Y must not be chosen independent from
 each other.

 Example:

 The participation criterion says that adding
 some ballots, that rank candidate A above
 candidate B, must not change the winner from
 candidate A to candidate B.

 Election method X satisfies the participation
 criterion in domain X. Reason: If candidate A
 was the winner in the original profile and if
 the original profile was in domain X, then this
 means that candidate A was the Condorcet winner
 and, therefore, that candidate A pairwise beat
 candidate B. If candidate B is the winner in
 the new profile and if the new profile is in
 domain X, then this means that candidate B
 is the Condorcet winner and, therefore, that
 candidate B pairwise beats candidate A. If
 candidate A pairwise beat candidate B in the
 original profile and if candidate B pairwise
 beats candidate A in the new profile, then
 this means that the added ballots rank
 candidate B above candidate A.

 Election method Y satisfies the participation
 criterion in domain Y, because the Borda method
 satisfies the participation criterion in general.

 However, election method Z doesn't satisfy the
 participation criterion since the Condorcet
 criterion and the participation criterion are
 incompatible.

 In short: Even if election method X satisfies
 criterion A in domain X and election method Y
 satisfies criterion A in domain Y, it doesn't
 mean that election method Z satisfies
 criterion A. Therefore, Maskin's argumentation
 doesn't work.

 ***

 I also question the claim that the Borda
 method is the best possible election method
 in situations without a Condorcet winner.

 Markus Schulze

 
 Election-Methods mailing list - see http://electorama.com/em for list info

Election-Methods mailing list - see http://electorama.com/em for list info


[EM] Something better than wv for Schulze's CSSD

2011-06-21 Thread fsimmons
I am more convinced than ever that the best way to measure defeat strength in 
Beatpath (aka CSSD) is 
by giving the covering relation the highest priority, and where neither 
alternative covers the other, falling 
back on winning votes.  This is a natural way to extend the covering relation 
(which is a partial order) to a 
total ordering of the candidates.

So if A covers B, then that beatpath with one link is stronger than any 
beatpath that B can have to A.

If neither A nor B covers the other, then all beatpaths in both directions have 
links (defeats) that are not 
coverings (because the covering relation is transitive).  The strength of a 
beatpath that has at least one 
link that is not part of the covering relation is the wv strength of the 
weakest such link.

If we say that AB whenever the strongest (in the above sense) beatpath from A 
to B is stronger than 
any beatpath from B to A, then the  relation is a total order barring exact 
ties at weakest links. If 
range style ballots are used to infer the voter rankings, then these ties can 
be resolved without use of 
randomness.

Among the tied candidates give preference to the one with positive ratings on 
the greatest number of 
ballots.

If the tie is still not resolved, break it by giving preference to the still 
tied candidate rated above one on 
the greatest number of ballots.  If still tied, give preference to the still 
tied candidate rated above two on 
the greatest number of ballots, etc.

If we use the above method of defining defeat strength, we can still use the 
CSSD algorithm to find the 
Beatpath winner.  The method retains its clone free property, and its 
compliance with the Monotonicity 
Criterion.  Beyond that it always elects an uncovered alternative.

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Re: [EM] Eric Maskin promotes the Black method

2011-06-21 Thread robert bristow-johnson


On Jun 21, 2011, at 7:56 AM, Markus Schulze wrote:


Hallo,

Eric Maskin, a Nobel laureate, is currently very
active in promoting the Black method.


i have to confess, even though i had heard of ranked-choice voting  
before and had myself thought that what would later to be learned is  
called Condorcet compliant was the only logical and consistent (with  
a simple majority binary vote in all binary cases) manner to decide  
it.  and i thought of the possible problem that there was no single  
candidate who wins every pair they're in, didn't know what to call it,  
and didn't even know if there were any theorems that spoke to it, and  
decided not to worry about it.


anyway, because i'm a real neophyte to this, it wasn't until sometime  
last decade that i read anything about it until i read a Scientific  
American article of his titled The fairest vote of all that promoted  
Condorcet, but didn't really call it that.  Maskin labeled the method  
true majority rule and only obliquely raised the issue that a cycle  
could happen and mentioned Condorcet in that context.  soon after i  
learned the terms from the Wikipedia articles and at about the same  
time, we voted in IRV by about 65% (which was repealed in 2010 in a  
dramatic but really stupid slugfest between the one true faith One  
person, one vote crowd and those who denied anything went wrong in  
the 2009 election).


anyway, especially after reviewing his bio again, i can't help by  
admire the guy and it was an article of his that first got me thinking  
analytically about the voting systems issue.  but i wonder if he was  
using terminology that was more neology, even pre-neology.  i think he  
was trying to coin a term that would end up getting attached to his  
name.


and we've all been groping for a name for this primary voting criteria  
that is not this non-American, Frenchie, probably sorta pinko- 
socialist secular humanist intellectual (did i mention *not*  
American?) whose heresy is leading us away from the One True Faith of  
the Single Affirmative Vote.  we have sects in the One True Faith,  
some of us believe in the sanctity of the Two Party System: if yer  
ain't fer us, you agin' us.  and pass da ammunition, Ma.


i don't have a better idea than true majority rule.  but there must  
be a better one than that.  Warren, i remember you like beats-all  
winner for the CW.  i wonder if the beats-all method is a good label.




The Black
method says: If there is a Condorcet winner, then
the Condorcet winner should win; if there is no
Condorcet winner, then the Borda winner should win.



i hadn't heard of the Black method before, but just reading this shows  
pretty superficially a problem.  above is one way to say something...



See e.g.:

1 Sep 2009: http://research.microsoft.com/apps/video/default.aspx?id=143268
8 Apr 2011: http://www.youtube.com/watch?v=Bx_lt06W9Ww

Maskin argues as follows:

  If election method X is the best possible
  election method in domain X and if election
  method Y is the best possible election method
  in domain Y and if domain X and domain Y are
  disjoint and if domain X and domain Y together
  cover all possible situations, then the best
  possible election method is to use election
  method X in domain X and election method Y in
  domain Y.

Maskin argues: domain X = situations with a
Condorcet winner; election method X = any
Condorcet method; domain Y = situations
without a Condorcet winner; election method Y
= Borda method.



... and this is another way to say the same thing.  so, right away,  
Maskin is just restating an assertion as some sort of argument  
supportive of the assertion, but it is nothing new.  just a re- 
assertion.  (is that what is begging the question is?)


at the core, let's assume that we are already disciples of Condorcet,  
we all agree that method X is best for domain X, he doesn't say squat  
about why method Y is preferred in domain Y.  if we're nowhere near to  
a conclusion that Borda is good for anything (he might have been a  
good general, i dunno), then how do we conclude that it is preferable  
to everything else when there is no CW?  sorry, i haven't even got  
past this block.




Maskin's argumentation doesn't work because
of the following reason: Whether an election
method is good or bad depends on which criteria
it satisfies. Most criteria say how the result
should change when the profile changes. Now it
can happen that the original profile and the
new profile are in different domains. This
means that, to satisfy some criterion, election
method X for domain X and election method Y for
domain Y must not be chosen independent from
each other.



but, this is the fundamental argument of those who claim that it is  
natural for an election to be spoiled, to be dependent upon irrelevant  
alternatives.  isn't that what the fundamental issue is about for why  
Condorcet (assuming a CW exists) is consistent with any simple- 
majority, two-candidate