[EM] Methods of elimination in quota preferential STV

[David Catchpole]

Oh sheet- correction----

On Thu, 5 Oct 2000, David Catchpole wrote:

> But aren't all those alternatives also exclusion schema? The exclusion
> scheme I suggested was that, rather than excluding on the basis of first
> preference aggregates, when an exclusion has to be made, one does it by
> "electing" the nC-1 candidates who will not be excluded. For instance,
> with 1 to be elected and 4 candidates, and first preferences
> 
> 10	20	26	44
> A	B	C	D
> 
> one would "elect" 3 non-excluded candidates. The quota is 100/4 = 25
> 
> so C and D are "elected." C and D's votes are then redistributed. Say C
> voters usually favour B and D voters usually favour A.
> 
> 10	20	1		16		3
> A	B	(Ex. C) B	(ex. D) A	(ex. D) B
> 
> So rather than A being elected, B is elected!
>

That's _excluded_, not elected! Aargh!.


 
> Craig Carey criticised this exclusion scheme because it was
> "untested." That's bullshit. Applied to an "anti-STV" example he's been
> peddling around recently, it reduces the strategic weirdness that can be
> caused by simple plurality exclusion.
> 
> On Thu, 5 Oct 2000, LAYTON Craig wrote:
> 
> > Yes, I am.  The exclusion of those with the least votes (transfered or
> > original 1st preferences) would seem to have the same problems as IRV, with
> > the possibility that it could fail fundamental tests like eliminating a
> > Condorcet winner (obviously this is much less likely than in IRV),
> > monotonicity &c.  Some alternatives would be to rank the votes using Borda
> > or Kemeny-Young &c. at the start, and progressively eliminate the lowest
> > ranked (courtesy of Markus Schulze) or eliminating the bottom candidates
> > using a quota, and redistribute their votes at a reduced transfer value (if
> > I understand Craig Carey correctly).
> > 
> > Craig
> > 
> > -----Original Message-----
> > From: David Catchpole [mailto:s349436 at student.uq.edu.au]
> > Sent: Thursday, 5 October 2000 9:47
> > To: 'election-methods-list at eskimo.com'
> > Subject: RE: [EM] Methods of elimination in quota preferential STV
> > 
> > 
> > I don't quite get you. Are you asking about alternatives to exclusion?
> > 
> > On Wed, 4 Oct 2000, LAYTON Craig wrote:
> > 
> > > Yep, but I was considering the basis for excluding candidates in the first
> > > place.  If, for a moment, you accept the system of electing by quotas and
> > > distributing surplus votes at fractional values (an assumption I might be
> > > less inclined to make after I've looked more closely at Craig Carey's
> > > arguments), the basis for eliminating candidates when you get to a round
> > of
> > > voting in which there is no candidate with a quota is still something that
> > > doesn't seem very clear.  In fact, once the eliminated candidates'
> > > preferences start affecting the count, the result seems to become
> > > increasingly arbitrary.
> > > 
> > > >Hi Layton,
> > > >
> > > >where Nc is the number of candidates remaining that have not been elected
> > > >or excluded, one can conduct a "sub" STV election of Nc-1 candidates. The
> > > >candidate left over can be excluded.
> > > 
> > > 
> > 
> > ----------------------------------------------------------------------------
> > ---
> > "I only said we'd make it across"
> > 				-"Road Trip"
> > 
> > 
> 
> -------------------------------------------------------------------------------
> "I only said we'd make it across"
> 				-"Road Trip"
> 
> 

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"I only said we'd make it across"
				-"Road Trip"