[EM] Why I think IRV isn't a serious alternative 2

[Kristofer Munsterhjelm]

Gervase Lam wrote:
>> Date: Wed, 24 Dec 2008 10:53:36 +0100
>> From: Kristofer Munsterhjelm <km-elmet at broadpark.no>
>> Subject: Re: [EM] Why I think IRV isn't a serious alternative 2
> 
> Sorry.  I have not been following this lengthy thread carefully.  Just
> been taking in the bits that I find 'interesting.'
> 
>> most PR systems have a threshold (either 
>> implicit or explicit). Perhaps real world implementation of Condorcet 
>> systems would have a "first preference" threshold, either on candidates 
>> or on sets: anyone getting less than x% FP is disqualified.
> 
> Either that or have IRV with a different candidate elimination method
> (i.e. not the one with the least number of top votes)?  I dunno.

Or, as someone else proposed, a Condorce method where A > B, for all B, 
  is weighted to some multiple if A is the first preference.

>> For instance,
>>
>> 49: Faction A controls nation > Compromise > Faction B controls nation
>> 48: Faction B controls nation > Compromise > Faction A controls nation
>>   2: Compromise > Faction A controls nation = Faction B controls nation
>>
>> That's kinda contrived, but if either A or B wins, there'll be big trouble.
> 
> Doesn't this depend on how good Compromise is?  It is impossible to tell
> just from the above.

I was considering an unstable nation where the A and B groups want to 
destroy each other. Even if the compromise is a near standstill, it's 
better than having a war.

Still, your point is taken. The problem with ordinal methods is that you 
can't specify strength; but that's also, in some sense, an advantage, 
since that means the method is less prone to being tricked by noise or 
by optimization. Which matters more is a question of perspective and 
what you want out of the method.