[EM] Three rounds

[Juho Laatu]

--- On Thu, 13/11/08, Kristofer Munsterhjelm <km-elmet at broadpark.no> wrote:

> I think that in order to get anywhere on this path, we
> would have to know what it is we actually want from a
> runoff.

First I want to note that I don't want to promote runoffs, just to study them.

> There are two reasons why you might have a runoff:
> the honest, that voters can discuss which of the two
> candidates are better without having to consider the others,

Sometimes it may be possible to achieve the same effect my publishing polls before the election.

> But what's a viable candidate? Is
> it viable if in Smith (or mutual majority, or whatnot)?

Mutual majority makes more sense than Smith.

In the given example A, B and C formed a strongly looped Smith set, and D was a Condorcet loser (but not by mutual majority) that was almost a Condorcet winner. In this situation also D could be a viable candidate for the last runoff round.

> > The party lists could be more interesting when
> breaking Condorcet
> > cycles. But in a runoff one could first vote between
> parties and only
> > then between candidates of the winning party. I'm
> not sure that this is
> > very useful, but this way one could e.g. reduce the
> risk of the best
> > compromise candidate of a party being eliminated too
> early.
> > 
> > For example
> > 40: A1>A2>B>C
> > 08: A2>A1>B>C
> > 07: A2>B>A1>C
> > 25: B>A2>C>A1
> > 20: C>B>A2>A1
> > A2 would be eliminated first in IRV but here A1 and A2
> form a party
> > (with 55 first preference votes) and therefore C will
> be eliminated
> > first, B next, and then A2 will win.
> 
> This seems to be more of a problem with IRV, and so I'd
> say that a better solution would be to switch to another
> voting system rather than try to patch it up with party
> lists.

Yes, this is a problem of IRV. Yes, there may be better methods than the IRV based ones. Use of parties may provide some limited benefits, but they add complexity too.

Juho