Anthony Duff | 1 Jul 04:32 2003
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Use a turkey filter

I think the turkey issue is a real problem for
condorcet and approval.  A simple solution is to
filter out the turkeys before they get on the ballot.

 --- Adam Tarr <atarr <at> purdue.edu> wrote: 
> 
> That said, I have argued in both my recent messages
> that it's pretty 
> ridiculous to expect a candidate with
> undifferentiated opinions to get a 
> vote, even a lower place vote, from nearly the
> entire electorate.  People 
> are not so easily duped, especially when the leaders
> of the political 
> factions would be advising them to not cast a vote
> for Mr. anonymous in 
> these situations.
> 
> -Adam

I don’t think it is ridiculous at all, it is in fact a
probable outcome.

Consider the Australian example.  Ballots are ranked. 
Equal rankings are not allowed, except that truncation
sometimes is.  The count is conducted by IRV, not
Condorcet, but I argue that that is nearly irrelevant
– the masses are fully occupied , 1st, with decided
which candidate they will prefer, and 2nd, with
following the instructions on how to complete their
(Continue reading)

Adam Tarr | 1 Jul 08:13 2003
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Re: request for reading matter

At 11:29 PM 6/30/2003 -0400, John B. Hodges wrote:

>I've heard of "ranked pairs", but what is "beatpath"? I presume it is a 
>method of resolving Condorcet elections in case of circular pairwise 
>pluralities. Where can I read about the properties, mathematical and 
>otherwise, of Ranked Pairs and Beatpath?

One good site to check out is Rob LeGrand's: 
http://www.onr.com/user/honky98/rbvote/.  This site has good explanations 
of a whole slew of ranking methods.  Beatpath and Ranked Pairs are referred 
to as Schulze and Tideman, respectively.  This web site also has a nice 
vote calculator, whose only drawback (in my opinion) is that it forces 
margins-based results.

Some other good web sites by folks on this list:

Eric Gorr's voting calculator: http://www.ericgorr.net/condorcet/index.php 
is very good, and can be used to do either Ranked Pairs or Beatpath; 
winning votes or margins.

Mike Ossipoff's http://electionmethods.org/ - very solid site that supports 
Approval and Condorcet and criticizes IRV.

Blake Cretney's http://condorcet.org/ - the election method resource 
section is especially good.

The collective project of http://www.wikipedia.org/wiki/Voting_system - 
it's getting better.

But most significantly, if you ever get confused, you can always try 
(Continue reading)

Eric Gorr | 1 Jul 15:45 2003
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Re: request for reading matter

At 1:13 AM -0500 7/1/03, Adam Tarr wrote:
>Eric Gorr's voting calculator: 
>http://www.ericgorr.net/condorcet/index.php is very good, and can be 
>used to do either Ranked Pairs or Beatpath; winning votes or margins.

Thanks... :-)

Slight correction...I do winning votes, not margins. Ok, well, I do 
use margins, but only in the case where I have two pairwise victories 
of equal strength, from the point of view of winning votes. In that 
case, it is reasonable to use the margin of the victory to determine 
how to rank them.

--

-- 
== Eric Gorr ========= http://www.ericgorr.net ========= ICQ:9293199 ===
"Therefore the considerations of the intelligent always include both
benefit and harm." - Sun Tzu
== Insults, like violence, are the last refuge of the incompetent... ===
----
Election-methods mailing list - see http://electorama.com/em for list info

Adam Tarr | 1 Jul 17:21 2003
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Re: request for reading matter

Eric,

You're right of course - all I meant by that was that a calculator that 
uses winning votes can be made to produce the margins result.  All you have 
to do is replace all truncation with an even split of votes.  For example, 
if A beats B pairwise, 40-30, with 30 voters not voting, then replacing 
that with A beating B 55-45 will give the equivalent margins result.

Of course, I prefer winning votes, so I wouldn't do that.  But the option 
is there.

-Adam

Eric Gorr wrote:

>At 1:13 AM -0500 7/1/03, Adam Tarr wrote:
>>Eric Gorr's voting calculator: 
>>http://www.ericgorr.net/condorcet/index.php is very good, and can be used 
>>to do either Ranked Pairs or Beatpath; winning votes or margins.
>
>Thanks... :-)
>
>Slight correction...I do winning votes, not margins. Ok, well, I do use 
>margins, but only in the case where I have two pairwise victories of equal 
>strength, from the point of view of winning votes. In that case, it is 
>reasonable to use the margin of the victory to determine how to rank them.
>
>
>--
>== Eric Gorr ========= http://www.ericgorr.net ========= ICQ:9293199 ===
(Continue reading)

Forest Simmons | 2 Jul 21:47 2003

CR/Approval

Here's another method that makes use of CR ballots to enhance Approval:

Each voter rates each candidate on some scale, say zero to 100%.

The ballots are counted in two stages:

In the first stage the approval cutoff for each ballot is a rating of 50%.

In the second stage the approval cutoff on a ballot is the rating of the
first stage winner on that ballot.

In each stage on each ballot each candidate above the cutoff (for that
stage) gets 100% approval, while each candidate below the cutoff gets zero
approval, and each candidate precisely at the cutoff rating gets a
percentage of approval equal to the cutoff rating.

The winner of the second stage is the method winner.

[end of description of method]

The idea is that if you knew the sincere approval winner, you would
probably want to use that candidate as your approval cutoff if you had a
second chance.

The question is should you approve the cutoff candidate C?

This method says that you should give this cutoff candidate C more or less
approval according to how high you rate C.

If you rate C 100%, then you should give C 100% approval.
(Continue reading)

Adam Tarr | 2 Jul 22:43 2003
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Re: CR/Approval

Interesting idea Forest.  This method basically simulates a two-stage 
repeated approval balloting, with one significant difference - that the 
winner of the first round gets partial votes in the second round.

This effect actually creates some problems.  If I prefer the first round 
winner to his closest competitor, then I have an incentive to insincerely 
rank the (expected) first round winner at 100%, so that I cast the full 
mark for him in the second round.  This of course forces me to rank 
everyone I like more at 100% as well.  Conversely, if I prefer the closest 
competitor to the first round winner, I have an incentive to rank the 
expected first round winner at 0%, which forces me to do the same for 
everyone I like less.

The way to avoid this seems to be to incorporate some approval strategy in 
the way the second round votes are done.  I'd suggest using the generally 
accepted strategy for good information:  "approve all candidates I prefer 
to the current first-placer; also approve the first-placer if I prefer him 
to the second-placer."  This means every candidate gets either 100% 
approval or 0% approval in the second vote.  This removes the incentive to 
stack all the rankings toward the top or bottom.

The advantage of this approach is that it basically allows all the voters 
in an approval election to make fairly intelligent votes without having to 
think about it.  The disadvantage is that, by getting rid of the partial 
votes for the cutoff candidate, we have lost the most direct link to utility.

I assume the strategy in this method involves manipulating which candidates 
finish top two in round one, which determines the cutoffs in round two.

-Adam
(Continue reading)

Forest Simmons | 3 Jul 21:38 2003

Re: CR/Approval

Good points in the critique below.

Here's another way to get around the problem of deciding whether or not to
approve a candidate whose rating precisely matches the approval cutoff:

Use an even number CR resolution, so the max value is odd, for example CR
values from zero to three.  Then the first stage approval cutoff is an
half integer value (in this case 1.5), a value occupied by no candidate.

In the second stage use for a cutoff value the average of the old cutoff
value and the CR of the first stage winner.

In the zero thru three example this value will be of the form (n/2) + .75,
so it will not be the CR of any candidate.

This method gives equal weight to the first stage winner CR and the zero
info cutoff value in determining the second stage cutoff value.

If the voter wanted to, she could award only the extreme CR values.  That
would be equivalent to casting an approval ballot.

But it seems to me that there would be some advantage in using the two
middle levels as well.

In the case of eight levels (zero thru seven) it might be good to have
four stages, because that is how many stages it would take before the
cutoff could possibly distinguish between zero and one, or between six and
seven.

At the fourth stage the cutoff level would be (r1+r2+r3+3.5)/4, where the
(Continue reading)

Bart Ingles | 4 Jul 00:36 2003
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Citizens for Approval Voting


http://approvalvoting.org

> -- Nobel Prize Winner Adds Support to Approval Voting Movement --
> 
>   Dr. Dudley R. Herschbach of Harvard, who was a co-recipient of the Nobel 
> Prize for Chemistry in 1986, has added his support to Citizens for Approval 
> Voting. Dr. Herschback co-wrote the article "The Science of Elections" along 
> with New York University professor Steven J. Brams. This article was 
> published in the May 25, 2001 edition of Science Magazine.
> 
>   Dr. Herschbach joins other notable academic opinion leaders in choosing
> to support a move taway from plurality voting and towards Approval Voting. A 
> few of the other notables include:
> 
>  - Dr. Robert J. Weber of NorthWestern University;
>  - Dr. Stephen J. Brams of New York University;
>  - Professor Jack Nagel of University of Pennsylvamia; and
>  - Professor Sam Merrill of Wilkes University.
> 
[...]
----
Election-methods mailing list - see http://electorama.com/em for list info

Kevin Venzke | 4 Jul 00:25 2003
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A few short replies

First, I want to clarify that I don't claim Condorcet's "turkey problem" is a
serious issue.  If plain Condorcet were as easy to explain and hand-count as Approval,
I would easily prefer it to plain Approval.

Douglas Gamble wrote:
>Under Condorcet by casting a second preference for compromise candidate 
>B both A and C voters have effectively defeated their first choice and elected 
>B.

I assume you realize that each faction is defeating the OTHER faction's first
choice, not their own.  That detail may not matter to you, but in truth their
lower preference for B is not hurting their own favorite.

James Green-Armytage:

That was a great message.  I agreed with every bit of it.  My only slight difference
of opinion would be that I think single-winner Condorcet/Approval/etc. is still a
good idea for legislatures.  Perhaps a legislature could be mixed PR/single-seat,
but I think that deciding policy with a solely PR-based legislature is as bad as
electing single winners with plurality.

John Hodges wrote:
>Whether IRV is the best method possible is 
>open to debate; but it ain't all THAT bad. C'mon, people.

I think it is comparably bad to plurality, because it still encourages two-party
dominance.  An electoral method that can't even avoid that, in my view, isn't
worth the effort to implement.

You also said:
(Continue reading)

Adam Tarr | 4 Jul 07:50 2003
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Re: Nightmare On IRV Street ?

David Gamble wrote:

All single seat methods are capable of producing bad results.

Of course, they are only bad from some point of view.  But yes, I'd agree with that in principle.  That said, some will produce bad results much more reliably than others.

This is why I believe that single member methods should only be used for single offices ( mayor, governor, president, etc) and that multi-member bodies should be elected by proportional representation. There is nothing and can be nothing that is proportional about the allocation of a single seat.

That's a laudable goal.

 My preferred single member method is IRV.

That's a pretty big non sequitur there.  Why IRV?  Simply because that's what the largest US electoral reform group supports?

Can you really put the Condorcet "nighmare" scenario I wrote in the same ballpark as the IRV nightmare scenario?  My Condorcet scenario ends with the compromise candidate winning, and nobody regretting their vote.  In the IRV scenario I showed, the clearly, indisputably preeminent candidate loses, and a third of the electorate is kicking themselves on election night.

My preferred multi-member method is the single transferable vote. It is considered an important principle in STV that lower preferences should neither help nor harm higher preferences. The reason for this is that if by casting a lower preference you can defeat a higher preference you are given a powerful incentive not  to cast lower preferences.

This is also true of winning votes Condorcet the vast, vast majority of the time.  The scenario you mention below is no exception.

For example:

44 A>B>C
7 B>A>C
7 B>C>A
42 C>B>A

The election was to close to call, before the votes were counted it was uncertain whether A or C would obtain the most first preferences ( and also irrelevant considering A and C supporters second preferences).

Under Condorcet by casting a second preference for compromise candidate B both A and C voters have effectively defeated their first choice and elected B.

This is totally untrue.  As Kevin pointed out, they have only beaten the OTHER candidate, their least favorite, by casting second place votes.  Nobody in this election was hurt by their second place votes.  Not in the slightest.

Yes, I am aware that B is the most generally preferred candidate and that by voting for B C supporters have also defeated A.

That is, in fact, the only thing they have done.

If a A and C voters had not expressed a 2nd preference and voted

44 A
7 B>A>C
7 B>C>A
42 C

A would have won, or if two votes had been cast differently C would have won.

Sure, and in either scenario the losing faction says to themselves, "why didn't I vote for B?"  It can only help them, and can never hurt them.  Here, I'll show the decision matrix.  The top row is the vote of the A supporters, and the left column is the votes of the C supporters.  The corresponding matrix entry is who wins the election.  (This may look lousy, but if you cut and paste into something that has monotype spacing it will look fine):

----| A   | A>B |
----|-----|-----|
C   | A   | A   |
----|-----|-----|
C>B | B   | B   |
----------------|

Now, if C happens to have more first place support than A, the matrix in stead looks like this:

----| A   | A>B |
----|-----|-----|
C   | C   | B   |
----|-----|-----|
C>B | C   | B   |
----------------|

Now, lets combine the two matrices and show what the possibilities for each faction are.   The result for each faction if A has more votes are before the slash, and after the slash is if C has more votes.


----| A   | A>B |
----|-----|-----|
C   | A/C | A/B |
----|-----|-----|
C>B | B/C | B/B |
----------------|

So, for the A faction, voting their full preferences changes the result from C winning to B winning, or keeps the result the same.  Similarly, for the C faction, voting their full preferences changes the result from A winning to B winning, or keeps the result the same.  Voting a second preference will NEVER cause an adverse result for a faction in this election.

-Adam

Gmane