[EM] IRV vs Condorcet vs Range/Score

[Kristofer Munsterhjelm]

Dave Ketchum wrote:
> I suggest a two-step resolution:
>      Agree to a truce between Condorcet and Range, while they dispose of 
> IRV as being less capable than Condorcet.
>      Then go back to the war between Condorcet and Range.

I think the problem, or at least a part of it, is that if we (the 
election-methods members) were to advocate a method, to be effective, it 
would have to be the same method. Otherwise, we would "split the vote", 
as it were, against the status quo. Therefore, both Condorcet and Range 
groups would prefer their own method to "win".

If that's true, then one way of uniting without running into that would 
be to show how IRV is bad, rather than how Condorcet or Range is better. 
If there's to be unity (or a truce) in that respect, those examples 
would focus on the properties where both Range and Condorcet, or for 
that matter, most methods, are better than IRV, such as in being 
monotonic, reversal symmetric, etc.

An expected response is that these properties don't matter because they 
happen so rarely. To reply to that, I can think of two strategies. The 
first would be to count failures in simulations close to how voters 
would be expected to act, perhaps with a reasoning of "we don't know 
what strategy would be like, but the results would be worse than for 
honesty, so these provide a lower bound". The second would be to point 
to real uses, like Australia's two-party domination with IRV, or Abd's 
argument that TTR states who switched to IRV have results much more 
consistent with Plurality than what used to be the case.