[Election-Methods] Corrected "strategy in Condorcet" section

[Juho]

On Jul 31, 2007, at 2:52 , Abd ul-Rahman Lomax wrote:

> At 05:35 PM 7/30/2007, Juho wrote:
>
>> Yes, a more detailed analysis should not rely on one axis only.
>
> I'm not sure how many Warren's simulations use, but the simulator  
> doesn't just do even random distributions, which are unrealistic,  
> though interesting.
>
>
>> The additional (utility/preference strength related) information that
>> range style ballots provide is excellent information. The only
>> problem is that we don't have a voting method that would both take
>> that information properly into account and be resistant to strategic
>> voting at the same time.
>
> I've suggested one. Why not consider it?

I have given it some consideration. I think I have also commented  
this type of methods few times.

>
>> Condorcet votes are relatively expressive (less than Range but more
>> than most) and at the same time they are relatively resistant to
>> strategic voting. That's why they are interesting and why they may be
>> a good or the optimal method for many uses.
>
> Problem is, they can make spectacularly bad decisions with people  
> voting sincerely! It's inherent in the Codorcet Criterion, which  
> utterly neglects preference strength, turning a fly's weight of  
> preference into something equivalent to life or death. (I.e., both  
> preferences are considered equally.)

Could you present the concrete example where this happens. I actually  
just posted one example in my recent mails where the winning votes  
pick a candidate that doesn't seem to be a reasonable choice. But  
maybe you see the world from the Range perspective and refer to some  
example where Condorcet picks a candidate with low sum of utilities.

>
> Range is an excellent method for use in small groups as a poll, to  
> suggest a nominee. You wouldn't use Condorcet for that, not if you  
> know what is good for your group! You are going to ratify the  
> result anyway, small groups have the luxury of that, so the result  
> *must*, with good procedure, satisfy the *ultimate* Condorcet  
> Criterion.

Note that I don't consider the Condorcet criterion to be the ultimate  
criterion (and I have told this to you about 5 times :-). In non- 
competitive elections I'd be happy to use Range and allow a candidate  
that is not a Condorcet winner (the one that would beat all others in  
pairwise plurality elections) to win. Condorcet criterion is a good  
rule for competitive elections though.

>
> The Condorcet Criterion is problematic also because it can award  
> victory based on a small percentage of the electorate, the Majority  
> Criterion is much stronger. It's advisable, in my opinion, to never  
> award elections based on a plurality, period. The safest way to do  
> it is with a ratification, and we we really start to design  
> election methods both for efficiency and accuracy, we'll consider  
> that.

A "small percentage" example would make thing clearer to me.

It appears that most discussion on Condorcet and competitive  
elections focuses on making the Condorcet completion methods (or  
Condorcet related but not Condorcet compliant methods) strategy  
proof. There is too little discussion on which candidate would be the  
best to elect.

Concerning combinations of ratings and rankings I still feel that in  
competitive situations ratings can provide useful additional  
information and guidance but including the rating info in the  
selection algorithm is quite complex. One interesting example on how  
to use ratings in Condorcet completion is in http://fc.antioch.edu/ 
~james_green-armytage/cwp13.htm.

>
>
>> Theoretically, in a two party system the opinions of the two parties
>> should change in time so that the average voter opinion would lie
>> approximately between the two parties.
>
> Median, not average.... That's the theory. However, it can go  
> spectacularly wrong.

Median is more correct. I was obviously thinking in terms of binary  
opinions that are typical in the two-party voting process.

In politics many things can go wrong. Let's continue improving the  
mechanisms. They may provide some help.

Juho

>
>


		
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