[EM] Methods

[Dave Ketchum]

Quoting Mike Ossipoff:  'to me, our current public political elections  
don't require any strategy decisions, other than "vote for acceptable  
candidates and don't vote for the entirely unacceptable ones."'

In the discussions of Approval and ranking, below, Mke's thought  
applies to both.  In the extreme, when this leaves no one to vote for,  
simply vote for none (or, if forced, do whatever forced to do for one  
candidate).

In Approval we have a count of how many considered each candidate  
acceptable; with ranking we have counts in an x*x matrix as to how  
many preferred each candidate over each other candidate.

On Oct 18, 2011, at 4:28 PM, Kristofer Munsterhjelm wrote:

> matt welland wrote:
>> On Mon, 2011-10-17 at 20:42 +0200, Kristofer Munsterhjelm wrote:
>>> matt welland wrote:
>>>> Again, I think it is very, very important to note that the ranked
>>>> systems actually lose or hide information relative to approval in  
>>>> both
>>>> these cases.
>>> In what manner does a ranked method hide information? Neither  
>>> ranked ballot methods nor strategic Approval can distinguish  
>>> between "everybody's equally good" and "everybody's equally bad".
>>>
>>>> Note that in the first case the results and impact of a ranked  
>>>> system
>>>> are actually worse than the results of approval. The political  
>>>> pressure
>>>> to converge and appeal to a broad spectrum is greater under  
>>>> approval
>>>> than the ranked systems. The evaluation of a voting system only  
>>>> makes
>>>> sense in the context of all the other things going on in a  
>>>> society. The
>>>> pressure on politicians to actually meet the needs of the people  
>>>> is a
>>>> massively important factor and ranked systems appear to wash out  
>>>> some of
>>>> that force which is a very bad thing IMHO.
>>> Again, why is that the case? In Approval, you're either in or  
>>> you're out; but in ranked methods, the method can refine upon  
>>> those two groups and find the better of the good (be that by broad  
>>> or deep support relative to the others). If anything, this finer  
>>> gradient should increase the impact, not decrease it, because the  
>>> search will more often be pointed in the right direction.
>> A ranked system cannot give the feedback that all the candidates are
>> disliked (e.g. all candidates get less than 50% approval). It also
>> cannot feedback that all the candidates are essentially equivalent  
>> (all
>> have very high approval).

While it is agreed that counts in Approval show the above, it needs  
seeing that the x*x matrix can be read in the same way for ranking.

> Neither does strategic Approval. In Approval, the best simple  
> strategy (if I remember correctly) is to approve the perceived  
> frontrunner you prefer, as well as every candidate who you like  
> better. In a Stalin election, if people were perfectly rational, the  
> left-wingers would approve Stalin if the other frontrunner was Hitler.
>
> Well, perhaps people aren't perfectly rational. However, to the  
> degree they are honest, Approval can get into a contending third- 
> party problem. If you have a parallel universe where Nader is nearly  
> as popular as Gore, liberals would have to seriously (and  
> strategically) think about whether they should approve of Gore or  
> not - if too many approve of Gore *and* Nader, Nader has no chance  
> of winning; but if too many approve of only Nader, Bush might win.
>
>> Ranked systems essentially normalize the vote. I think this is a  
>> serious
>> issue. A ranked system can give a false impression that there is a
>> "favorite" but the truth might be that none of the candidates are
>> acceptable.

See above.
>
>
> Some ranked methods can give scores, not just rankings. As a simple  
> example, the Borda count gives scores - the number of points each  
> candidate gets - as a result of the way it works. The Borda count  
> isn't very good, but it is possible to make other, better methods  
> give scores as well; and if you do so, an "equally good/equally bad"  
> situation will show as one where every candidate gets nearly the  
> same score.
>
> As for distinguishing "equally bad" from "equally good", there are  
> two ways you could do so within ranked votes. You could do it  
> implicitly, by assuming that the voters approve of the candidates  
> they rank and disapprove of those they don't; or you can do it  
> explicitly by adding a "against all" (re-open nominations, none of  
> the below, etc) virtual candidate.

Adding a virtual candidate is making trouble for voters UNLESS its  
good justifies its pain.
>
>
>> Ironically by trying to capture nuances the ranked systems have  
>> lost an
>> interesting and valuable part of the voter feedback.
>> A voting system should never give the impression that candidates that
>> are universally loathed are ok. If our candidates were Adol Hitler,
>> Joseph Stalin, Pol Pot, Idi Amin, Benito Mussolini, Mao Zedong and
>> Leopold II of Belgium then approval would rightly illustrate that  
>> none
>> are good candidates. However a ranked system would merely indicate  
>> that
>> one of them is the "condorcet" winner giving no indication that  
>> none are
>> acceptable.

Again, x*x is useful and available and ranking has no more need for  
sick ranking than does Approval.
>
>
> Here, an implicit solution would record heaps of blank votes, and an  
> explicit one would show the virtual candidate to be the CW.
>
>> I think any sane voting system *must* meet this requirement. The  
>> ability
>> for the electorate to unambiguously communicate that none of the
>> candidates are worthy of the post under contest. I don't know how  
>> to prove it but my hunch is that approval would be more
>> resistant to manipulation by the so-called "one percenter" elites  
>> than
>> ranked systems.

Apparently this theory was designed without adequate understanding of  
ranking.
>
>
> James Green-Armytage's paper seems to show Approval as one of the  
> rules more vulnerable to strategic voting (see http://www.econ.ucsb.edu/~armytage/svn2010.pdf 
>  ). Whether or not that would translate into one-percenter  
> manipulation, however, I don't know. I suspect that most of the  
> rules (e.g. various Condorcet methods, Approval, Majority Judgement)  
> would be sufficiently resistant. Even top-two seems to do well  
> enough to break Duverger's law.

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