[EM] Anyone got a good analysis on limitations of approval and range voting? (long)

[Kristofer Munsterhjelm]

Matthew Welland wrote:

> So, to re-frame my question. What is the fatal flaw with approval? I'm 
> not interested in subtle flaws that result in imperfect results. I'm 
> interested in flaws that result in big problems such as those we see 
> with plurality and IRV.

IMHO, it is that you need concurrent polling in order to consistently 
elect a good winner. If you don't have polling and thus don't know where 
to put the cutoff (between approve and not-approve), you'll face the 
Burr dilemma: If you prefer A > B > C, if you "approve" both A and B, 
you might get B instead of A, but if you "approve" only A, you might get C!

Thus the kind of Approval that homes in on a good winner employs 
feedback. The method is no longer Approval alone, but Approval plus 
polling. That /can/ work (people approve {Nader, Gore} if Nader has 
fewer votes than Gore, so that Bush doesn't win from the split, but only 
approve either Nader or Gore if both are large), but why should we need 
to be burdened with the feedback?

Some, like Abd, argue that we always reason based on others' positions 
to know how much we can demand, and so that this is a feature rather 
than a bug. That doesn't quite sound right to me. In any event, if you 
want Approval + bargaining (which the feedback resolves to), make that 
claim. Approval alone, without feedback, will be subject to the flaws 
mentioned earlier, however.