[EM] Election methods in student government...

[Gervase Lam]

> Date: Thu, 21 Dec 2006 18:36:06 +0100 (CET)
> From: Kevin Venzke
> Subject: Re: [EM] Election methods in student government...

> --- Tim Hull a ?crit?:
> > I'm curious - is there any other multi-winner PR methods (besides STV)
> > that
> > satisfy later-no-harm, exclusing variants of party list and asset?  Also,
> > what tie-breaking methods for IRV/STV/MMPO satisfy LNH?
> 
> For MMPO (where ties are a big issue) the most obvious tiebreaker would
> be first preferences. You could also do random ballot.
> 
> MMPO elects the candidate against whom the greatest pairwise opposition
> is the least. Here's an extreme situation of this:
> 
> 1000 A
> 1 A=C
> 1 B=C
> 1000 B
> 
> C wins. I suggest less sensitivity to pairwise opposition scores of
> under a majority. I recently suggested (as the "MTR" method) a version
> that reduces all scores to "majority" or "less than a majority" and
> resorts to the first preferences tiebreaker more often.

IRV satisfies LNH but strictly speaking does not allow equal rankings.
MMPO satisfies LNH but allows equal rankings.  Would there be any
benefits in disallowing equal rankings in MMPO?

Thanks,
Gervase.