[EM] Methods of elimination in quota preferential STV

[David Catchpole]

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!

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"
> 
> 

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