[EM] simulator code for 2 Approval methods

[Kevin Venzke]

Raphfrk,

--- raphfrk at netscape.net a écrit :
> From: stepjak at yahoo.fr
> > Thanks. Looking at that result, compared with other methods' results
> > on your site, and noting that the original study obtained nearly the
> > same results for Approval and Condorcet... I have to wonder if there
> > isn't something wrong here. Is it possible that there are many ties
> > occurring between green and red, that are being broken invariably in
> > favor of red? If so we'll have to be more careful about that...
> 
> You could be right.  2 candidates could easily be above the threshold and
> thus get exactly the same totals.  The function breaks ties the same
> way every time.  The way to check it would be to take a random experiment
> and reverse the order of the candidates.

Yes, this should definitely be tried.

> In general, the simulation could be setup so that it runs 2 elections
> with
> the candidates order forward and 2 elections with the candidates ordered
> backwards instead of 4 ordered forwards.  If candidate order matters, 
> then there would be areas which are solid mixed colour.

Well,
1. This isn't a perfect solution since it will still fail when there
are ties among three candidates.
2. This is a much bigger problem for Approval methods than other methods.
So I'm not sure a general fix is required (or practical, really).
3. You can fix your Approval methods by considering the candidates'
scores in a random order. That should be pretty easy. Assign random
scores, sort, use that order.

> I think the 'poll' case should be alot better as it will allow the 
> virtual voters to place their threshold better.

Maybe... The poll itself will be flawed given three-way ties, and then
the actual election will have the same reporting error we are (probably)
seeing here.

I am expecting to see monotonicity failures for Approval-with-poll.

Kevin Venzke


	

	
		
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