[EM] Ranked Preferences, example calculations

[Juho]

On Oct 28, 2006, at 5:57 , Abd ul-Rahman Lomax wrote:
>>  But I'm trying to balance between different criteria
>> here.
>
> You are trying to balance between a broken criterion and an  
> effective one. The result can only be a reduction of effectiveness.
>
> (Technically, the Majority Criterion is not "broken." It is simply  
> a criterion, not a standard. But we have thought of it as a  
> standard for so long that I think it is time we explicitly point  
> out how it is defective if considered a standard. Majority  
> preference is *often* not the best choice. With pizza or Presidents.

I don't have any particular majority sympathies. It is good in many  
cases though, just like the range utility functions serves some other  
needs. Majority can e.g. be used to avoid civil wars (as an extreme  
example). One man one vote, about 50% of men on each side, bigger  
faction wins, no war. Sometimes it pays off to use majority instead  
of maximising utility. That in a way gives something to every  
citizen, their say. Majority can also be said to maximise the number  
of people who feel themselves happy winners.

> Much of the time, maybe most of the time, the Range winner and the  
> Preference winner at the same. But it is when they are not that  
> something deeper is needed. I don't think it is possible to  
> incorporate that something in a single election. What is needed is  
> deeper deliberation, which is why another vote is needed.

This is an interesting marriage of two systems. I'm not yet convinced  
that the package would keep all their benefits and leave all the  
problems out. And to me it would look natural that if one can do it  
with two elections, there are also chances to do it with one. Note  
that the Ranked Preferences proposal has very similar goals, to keep  
the basic virtues of the simpler methods (Condorcet) and at the same  
time include some additional preference strength information in the  
process (but in a one round election).

>>  One strict rule for me when designing this method was to keep
>> sincere voting possible and probable. If that would not have been the
>> goal I could have picked e.g. Range (that has good utility with
>> sincere votes, but that unfortunately can not maintain the sincerity
>> in contentious elections).
>
> This is simply a guess, and is probably a bad one.

Not just a guess. Many experts seem to take this as a truth. Of  
course it depends on how you define sincerity etc. but certainly the  
fact remains that Range behaves in different ways e.g. in neutral  
opinion polls and in competitive fights on the other hand.

>> Ranked Preferences tries to find one optimal spot in the space of
>> election methods. Let's see if it can be proven to fail or if it can
>> be improved.
>
> How long do we have to try? The *major* problem with present  
> election methods is, I'd judge, the complete neglect of preference  
> strength.t

Not necessarily a fatal problem. I'd rather see that as an  
opportunity for improvement.

> There is an additional problem that some methods don't even select  
> the Condorcet winner, i.e., the Preference winner.

I don't require Condorcet criterion to hold if there are reasons to  
deviate from it (this is the case in Ranked Preferences where  
preference strengths may well make someone else the winner).

> A>>B>C
>
> is quite a different vote, with respect to B, than
>
> A>B>>C.
>
> But a ranked ballot does not collect this information, it only  
> could show
>
> A>B>C.

Ok, let's use Ranked Preferences. :-)

Juho Laatu

Send instant messages to your online friends http://uk.messenger.yahoo.com