[Election-Methods] A Better Version of IRV?

Chris Benham cbenhamau at yahoo.com.au
Sat Jul 12 23:01:44 PDT 2008


Forest,
"The voter ranks all she wants to and the remaining candidates are ranked (later, i.e. below) by the voter's 
favorite or perhaps, as Steve Eppley has suggested, by the voter's specified public ranking. 

Since IRV satisfies LNH, what's the harm in this?".
The harm is that voter's votes are used to help candidates that the voters may not wish to help.
It offends the principle that the voter should be fully in control of his/her vote.
Giving some voters (candidates) the power to fully control their own vote and also to complete
the rankings of some of the truncators offends the principle that as far as possible all voters
should have equal power.
"In Australia, where (in single winner elections) most of the voters copy candidate cards, this would save 
them a lot of bother."
In Australia the only significant "bother" stems from compulsory full strict ranking (for the vote to be
counted as valid).  How many or few voters choose to exercise their right to not follow their favourite's
ranking advice is no argument for removing that right.


>This particular horrible idea would create a strong incentive 
>for the major power-brokers to sponsor the nomination of a 
> lot of fake candidates just to collect votes for one or other
>of the major parties.

"Am I mising something here?"
Yes, but I'm not sure exactly what.

"I thought IRV was clone free."
It is, but that  isn't relevant.


>How do you think it "might be a valuable improvement"?? What 
>scenario do you have in mind?

"(Besides the aboved mentioned advantage):

In conjunction with the candidate withdrawal option, it might enable the (other) losing candidates to save the 
Condorcet candidate, or otherwise compensate for IRV's non-monotonicity."

I've previously made my case against the "candidate withdrawal option".

http://lists.electorama.com/pipermail/election-methods-electorama.com/2008-March/021463.html

http://lists.electorama.com/pipermail/election-methods-electorama.com/2008-March/021471.html

I don't see how IRV's failure to elect the Condorcet candidate is necessarily linked to its "non-monotonicity".
There are monotonic (meets mono-raise) methods that fail Condorcet, and some Condorcet methods that
fail mono-raise.

I'm not impressed with embracing some evil definites in exchange for some vague "mights".
>And what do you have in mind as "Australia's worst problems 
>with their version of IRV"?

"It has degenerated into a defacto second rate version of Asset Voting."

To the extent that that is true it can (and should) be fixed by simply allowing truncation.

>Why do you want to "stop" IRV? Do you agree with Kathy Dopp
>that IRV is worse than FPP?

"I would stop IRV if we could get a better method in its place.

If we cannot stop IRV, why not search for acceptable tweaks that would improve it?"
The short answer is because IRV isn't really amenable to "tweaks".  In terms of  positive
criterion compliances it isn't dominated by any other method, and has both good and quite
bad properties (averaging in my judgement to a "good" method).  "Tweaks" generally muck
up its good properties  without enough compensation in terms of fixing or patching up its
bad properties.
I think Smith (or Shwartz),IRV is quite a good  Condorcet method. It completely fixes the
failure of Condorcet while being more complicated  (to explain and at least sometimes to
count) than plain IRV, and a Mutual Dominant Third candidate can't be successfully buried.
But it fails Later-no-Harm and Later-no-Help, is vulnerable to Burying strategy, fails 
mono-add-top, and keeps  IRV's failure of  mono-raise and (related) vulnerability to
Pushover strategy.


"It is better than FPP in some ways and worse in others, especially in complexity."
With separate paper ballots for each race, I don't accept that IRV is all that "complex".
I think that you have somewhat dodged my question. 
 
"Do you think that Asset Voting is worse than FPP?"

No, on balance.

"Just to clarify, I think that Condorcet Methods and Range, though better than IRV, share this complexity 
defect with IRV to some degree.  I have suggested the same tweak for them.  

In fact, that is the essence of DYN, wihich is simply carrying this tweak to its logical conclusion in the case 
of Range, which is the only one of the three (Range, Condorcet, and IRV) that satisfies the FBC."
I find your  DYN method  less offensive than your "IRV tweak" suggestion because it is an "opt in" system
and to the extent that voters don't opt in it is just plain Approval (a not-too-bad method).


Chris Benham






Forest Simmons  wrote (Fri Jul 11 15:11:38 PDT 2008 ):
> Forest Simmons wrote (Sun Jul 6 16:36:32 PDT 2008 ): > 
> There is a lot of momentum behind IRV. If we cannot stop it, 
> are there some tweaks that would make it more liveable?
> Someone has suggested that a candidate withdrawal option would 
> go a long way towards ameliorating the damage.
> Here's another suggestion, inspired by what we have learned from 
> Australia's worst problems with their version of IRV:
> Since IRV satisfies Later No Harm, why not complete the 
> incompletely ranked ballots with the help of the rankings of the 
> ballot's favorite candidate?
> The unranked candidates would be ranked below the ranked 
> candidates in the order of the ballot of the favorite.
> If the candidates were allowed to specify their rankings after 
> they got the partial results, this might be a valuable improvement.
> Forest

Chris Benham replied:

> Forest,
> To me in principle voter's votes being commandeered by 
> candidates isn't justified.

Commandeered?  

The voter ranks all she wants to and the remaining candidates are ranked (later, i.e. below) by the voter's 
favorite or perhaps, as Steve Eppley has suggested, by the voter's specified public ranking. 

Since IRV satisfies LNH, what's the harm in this?

In Australia, where (in single winner elections) most of the voters copy candidate cards, this would save 
them a lot of bother.

> This particular horrible idea would create a strong incentive 
> for the major power-brokers to sponsor the nomination of a 
> lot of fake candidates just to collect votes for one or other
> of the major parties.

Am I mising something here?  I thought IRV was clone free.

> How do you think it "might be a valuable improvement"? What 
> scenario do you have in mind?

(Besides the aboved mentioned advantage):

In conjunction with the candidate withdrawal option, it might enable the (other) losing candidates to save the 
Condorcet candidate, or otherwise compensate for IRV's non-monotonicity.
 
> And what do you have in mind as "Australia's worst problems 
> with their version of IRV"?

It has degenerated into a defacto second rate version of Asset Voting.

> 
> Why do you want to "stop" IRV? Do you agree with Kathy Dopp 
> that IRV is worse than FPP?

I would stop IRV if we could get a better method in its place.

If we cannot stop IRV, why not search for acceptable tweaks that would improve it?

It is better than FPP in some ways and worse in others, especially in complexity.

Do you think that Asset Voting is worse than FPP?

Just to clarify, I think that Condorcet Methods and Range, though better than IRV, share this complexity 
defect with IRV to some degree.  I have suggested the same tweak for them.  

In fact, that is the essence of DYN, wihich is simply carrying this tweak to its logical conclusion in the case 
of Range, which is the only one of the three (Range, Condorcet, and IRV) that satisfies the FBC.

This tweak works best for Range, because (in the case of Range) the ballot that accomodate this tweak is 
of the extremely simple "Yes/No/Favorite" style.  The Favorite category could easily be augmented to 
include Eppley's "Published Ballots" idea.

Forest



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