[EM] Participation

Abd ul-Rahman Lomax abd at lomaxdesign.com
Mon Apr 26 10:22:24 PDT 2010


At 08:07 AM 4/26/2010, Kristofer Munsterhjelm wrote:
>Abd ul-Rahman Lomax wrote:
>>At 11:57 PM 4/24/2010, Kevin Venzke wrote:
>>>Hi Abd,
>>>
>>>--- En date de : Sam 24.4.10, Abd ul-Rahman 
>>>Lomax <abd at lomaxdesign.com> a écrit :
>>> > This is what is common with the
>>> > use of voting systems criteria to study methods. Scenarios
>>> > are created, sometimes cleverly, to cause a failure of a
>>> > criterion. Does it matter if those conditions never exist?
>>> > It should.
>>>
>>>For the simple question of whether the criterion is satisfied or failed,
>>>no it doesn't. Of course people then do go on to disagree about whether
>>>certain criteria are important, and why. There is nobody who thinks every
>>>single criterion is important.
>>That's right. But until utility analysis 
>>started to be done, the arguments had 
>>practically no foundation, they were just ideas 
>>about what democracy should look like, 
>>sometimes intuitions, and sometimes quite 
>>deceptive. Some criteria may be positively 
>>harmful, and Later No Harm is one of those. No 
>>method that maximizes utility can satisfy Later 
>>No Harm, no method that finds the best compromise winner can satisfy it.
>>And no method that maximizes social utility, 
>>overall satisfaction, can satisfy the majority 
>>or condorcet criteria, as fundamental as they 
>>seem, when only a single ballot is used. They 
>>can by using a second ballot to ratify (or 
>>reverse) an original election that finds the utility maximizer.
>
>To me it seems that wouldn't be the case either. 
>Consider the case of a top-two runoff (with 
>Range as the first round) where the two winners 
>are both supported by a minority. Then no matter 
>who wins the runoff, the method as a whole has 
>failed the Majority (and Condorcet) criterion.

The criteria are not designed to apply to 
multi-round elections. You can't even tell from 
the information given. What if more voters vote 
in the runoff? It happens, you know. A runoff is 
a separate election, that's very important to 
understand. If write-ins are allowed, or if the 
plurality preference is clearly in the runoff, as 
two examples, the Condorcet and Majority criteria 
are satisfied, assuming that the runoff method 
satisfies them. Bucklin doesn't satisfy 
Condorcet, technically, but in practice it does, 
I'm pretty sure. It does satisfy the Majority criterion, clearly.

>Unlikely? Perhaps, but one failure is enough. Of 
>course, you could then argue on basis of social 
>utility (as you have), but you can't say the method passes the criteria.

You had two elections. The first one failed. The 
votes in it may determine ballot position, but 
they do not have any effect on the winner. They 
are then like any nomination rules, for example 
petition signatures or party endorsements. We 
don't claim that a method fails Condorcet because 
the nomination processes don't allow a condorcet 
winner to appear on the ballot!

>One could also formulate criteria based on 
>score, for instance: "if a candidate X is given 
>more than half the points given by voters in 
>that election in total, he should win" - a score/Range version of Majority.

I'm actually proposing using a Range ballot for a 
Bucklin method as primary, then examining the 
ballot, if there is majority failure, for various 
kinds of winners, and then including the 
important ones on the runoff ballot. I do 
advocate allowing write-ins on the runoff ballot, 
so there are actually *no* eliminations, just a 
kind of suggestion. It's rare, but write-ins do 
win elections, sometimes. A situation where a 
Condorcet winner, by some quirk, got eliminated 
is a case where it quite well might happen; in 
this case, there would be good data from the primary.

Because I'd use Bucklin for the runoff as well, 
it's conceivable that a Cndorcet winner could 
fail there, but this can only happen when there 
are excessive approvals by the supporters of the 
Condorcet winner. Essentially, it's either bad 
strategy -- and it's bad strategy when there is 
no excuse, the Condorcet winners supporters 
should know that this is, indeed, a Condorcet 
winner in the primary -- or it is a case of small 
preference strength in the votes for the 
Condorcet winner, compared to large preference 
strength in the votes for the actual winner of 
the election. In other words, this is a case 
where the Condoret winner was not ideal.

That's rare, but if we somehow had the magic 
perfect voting system, it would find this 
situation and would thus fail the Condorcet 
criterion. The question I ask: is, then, 
Condorcet failure of this kind a Bad Thing, to be avoided?

But ordinarily the Condorcet Criterion is quite 
important. That's why I'd like to make sure tha 
this winner, if there is majority failure, ends 
up on the runoff ballot. It allows those 
supporters to make a real, informed choice. For 
the Condorcet winner to fail, they must accept 
it, they must, at least, stand aside and not 
insist. If they persist, and if the Condorcet 
winner remains such through the expression of 
exclusive preferences, which requires that their 
preference strength be strong, they will prevail. 




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