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

[Kristofer Munsterhjelm]

Greg wrote:
>> Date: Tue, 25 Nov 2008 09:16:34 -0500
>> From: Brian Olson <bql at bolson.org>
>> Subject: [EM] Why I think IRV isn't a serious alternative
>>
>> There's been a lot of discussion lately started by people who advocate
>> IRV. I'm mystified. Really? You really think IRV is a good system?
>> I've spent so long considering it to be pretty much junk that I really
>> am confused by that position. Here's my summary of why I think IRV is
>> junk.
>>
>> (from http://bolson.org/voting/irv/ )
> 
> I will believe that when I'm presented with a non-negligible number of
> actual IRV elections for public office that failed to elect the
> "right" winner. And for starters, you get to define what "right" is.
> Preferably something of the form: in Election X, IRV elected candidate
> Y but candidate Z was the right winner, because of [insert your
> criteria and evidence here]. The more such cases you have, the more
> convincing your argument. I've studied every IRV election for public
> office ever held in the United States, most of which have their full
> ranking data publicly available, and every single time IRV elected the
> Condorcet winner, something I consider to be a good, though not
> perfect, rule of thumb for determining the "right" winner. When you
> present a case in which IRV did not elect the right winner, maybe I'll
> agree or maybe I'll dispute your criteria, but at least then we'd be
> off the blackboard and into the world of real elections.

If IRV does elect the true Condorcet winner in all realistic elections 
(as opposed to the CW according to strategic ballots), and the 
Australian two-party (two and a third?) dominance arises from IRV, then 
that means that any Condorcet single-round single winner method will 
lead to two party dominance. That would be unfortunate. Of course, if it 
is the truth, no matter how unfortunate it is, it'll still be the truth; 
and in that case we should focus on multiwinner elections and PR instead.