[EM] Condorcet How?

[Dave Ketchum]

On Apr 9, 2010, at 2:37 PM, Juho wrote:
> On Apr 9, 2010, at 3:03 AM, Kevin Venzke wrote:
>> Hi Juho,
>>
>> --- En date de : Jeu 8.4.10, Juho <juho4880 at yahoo.co.uk> a écrit :
>>>> I more or less despise the election of A in this
>>> scenario:
>>>>
>>>> 49 A
>>>> 24 B
>>>> 27 C>B
>>>>
>>>> I believe the possibility of this outcome is a
>>> disincentive for a candidate
>>>> like C to run.
>>>
>>> The story behind these votes seems to be that C is
>>> ideologically close to B and its nomination makes A win
>>> instead of B. If C is ideologically close to B why don't the
>>> "B" voters vote "B>C" (and make C win)?
>>
>> Because the story is that C is not considered an established  
>> candidate
>> (or a frontrunner), and the B voters (if they actually prefer C,  
>> which
>> is not something I mean to suggest) will not condescend to rank C.
>> Depending on the method, they could hand the election to C by  
>> ranking C,
>> and/or alternatively compel C supporters to not vote sincerely.
>
> Ok, but the story is not quite flawless yet.
>
> Case 1: "B" voters did not notice C. B had 51 supporters before the  
> nomination of C. All that heard of C changed their opinion to "C>B".  
> If C is so obviously better than B then also some of the "A" voters  
> should have voted "A>C" (or "A>C" if they feel the other way around  
> for some reason). But it seems that also they did not notice C. It  
> is also strange that someone can get 27% support (clearly more  
> support than B) and still be unknown to so many of the voters.
>
> Case 2: "B" voters did notice C and liked C but didn't want to vote  
> for C. In this case the votes are not sincere but twisted for some  
> psychological reasons. (Also some part of "A" voters should have  
> ranked B or C if they noticed C.)
>
> It seems that the role of non-informed voters and/or non-sincere/ 
> mutinous voters and the surprising emergence of candidate C have a  
> strong role in the story, and all the blame (of not following the  
> story (and intended outcome) that was discussed above) can not be  
> put on margins alone.

I see "C>B" as showing these two being somewhat together.  Thus it  
makes sense for A to be competitive.  It is suspect that we get no B>C  
with this.
>>
>> The best scenario is for C to be able to run, be voted for  
>> sincerely, and
>> either win, or not affect the outcome at all.
>
> Yes, that would be ideal.
>
If it is possible for C to win then C being somewhat weaker in its  
effect seems certainly possible..
>>
>>> If C is
>>> ideologically far from B then most "B" voters may vote as
>>> they do now, but then maybe "A" voters should vote "A>B"
>>> (and make B win) (since C seems to be closer to B than A).
>>> It is hard to find an explanation to sincere votes like
>>> this. Or are these maybe strategic votes, e.g. so that
>>> sincere "A>B" voters have decided to vote "A"?
>>
>> The A voters will not vote A>B because A and B are considered the
>> frontrunners. (i.e. that is the scenario that concerns me.)
>
> Yes but also this means that "A" voters are badly misinformed when  
> none of them have heard of C or believe that C is weak although C  
> has 27% first place support (clearly more than B) and all that heard  
> of C "on the B side" voted for C.
>
I stay with my reading that B+C are somewhat together as opposites of  
A.  Also fits with C voters adding B as second choice to help defend  
against A.

Dave Ketchum
>>
>>>> Fundamentally, if I said only one thing: I don't
>>> believe that the margins
>>>> ranking of defeat strength (resulting from its
>>> treatment of unranked
>>>> candidates) is in agreement with what voters would
>>> expect and want.
>>>
>>> What would you consider to be a better approach than
>>> margins for sincere votes? (winning votes has also scenarios
>>> that may be questioned)
>>
>> Maybe Range? I guess I don't see that question as interesting or  
>> useful.
>
> Yes, Range could be considered more ideal at least for some uses  
> (when one wants to maximize the sum of utilities) (there are also  
> other alternatives like minimizing harm to some and seeking  
> majority). The problem of course is that it is so difficult to  
> collect sincere ratings. I think the question is important since  
> performance with sincere votes (= elect the correct winner) is  
> important.
>>
>>> (Note btw that in another mail I just mentioned also the
>>> possibility of allowing B and C to formally team up so that
>>> defeats within their team would not be considered as severe
>>> as defeats between A and the team.)
>>
>> This doesn't interest me much (same as Forest's suggestion of pre-
>> election agreements in DYN) because I'm not interested in the case  
>> that
>> a single party (for all practical purposes) nominates two candidates.
>> I don't think that will normally happen or be desirable under any
>> method. What I'm concerned with is the viability of a "third"  
>> option and
>> voting for the third option.
>
> I don't believe such strong methods like teaming would be generally/ 
> typically needed. But if there are problems then teaming may be a  
> good way to overcome them (they may e.g. quite efficiently cut out  
> any strategy considerations). I also understand that in some  
> environments all "agreements between parties" may be considered to  
> represent too much some "spirit of old times".
>
> In summary, maybe the "third" party explanation is more what you are  
> after than the "not heard of C" explanation. In the example "B" and  
> "A" voters were maybe from some old established parties and they did  
> not want to recognize the emergence of a "third" new strong  
> candidate. I believe such problems may well be temporary. If one  
> adopts a new method that allows also "third" candidates to run in a  
> meaningful way and with real chances to win if they have strong  
> enough support, then I'd guess the attitude and problems of ignoring  
> them and not ranking them could fade out very soon. The two main  
> contenders and voters that support them can not pretend any more  
> that other candidates do not exist (one can e.g. not play down a  
> candidate with 27% of the first preference votes).
>
> Juho
>>
>> Kevin Venzke