Normative principles of elections- Condorcet and Irrelevance of Alternatives (plus a brief hello and an STV clarification)

[David Catchpole]

BRIEF INTRO

Hi! My name's David Catchpole, and I'm a pretty unexciting second year
Science/Arts undergraduate at the University of Queensland, Brisbane,
Australia. I have an interest (one which at the moment is
close-to-totally-unrelated to my course) in electoral design and normative
electoral theory, especially regarding the "quota-preferential" tradition
in Australia. Yes, that's right, another pro-STVer (sounds moderately
naughty, but nothing compared to the "*scandal*" which clutters
alt.politics.elections currently) (I don't see what the point is-
Mitterand had a mistress, and to me he's still a hero!) to argue with!

After logging up several hours of dead ends searching for information and
discussion about this "hobby" of mine (gag!) I found this mailing list.
Thankyou! (By the way, if anyone would be of help in campaigning for
changes to Queensland's Local Government Act, I would ta them very muchly)

SELECTIVE TRANSFER IN SINGLE TRANSFERABLE VOTE SYSTEMS
("quota-preferential")

Anyway, I might start by responding to an item on the web-page which led
me here, which was asking for information about whether excess votes in
"q-p" are / should be selected by whether they were already transfered.

The fact is that those rules are variable, like much of "q-p"
(aproximate/infinitesmal transfer/quota, instantaneous quota, criteria for
exclusion). But a useful note may be that selective transfer is generally
the rule used in organisations where one monolithic bloc holds power.
This may be because of what I perceive to be an advantage to large voting
blocs from this method for transfer (and a corresponding disadvantage to
smaller groups of similar ballots). Only those votes which together vote
over a number of quotas will be transferred, and so there is little
reflection of "dissident" votes or smaller blocs. Effectively, this
telescopes the voting power of the large bloc (selective transfer may also
cause an increase in likelyhood/extent of dishomogeneity, though I haven't
had enough coffee to try to work out how this may happen- it's basically a
hunch).

NORMATIVE PRINCIPLES OF ELECTIONS- CONDORCET AND THE IRRELEVANCE OF
ALTERNATIVES

An unfortunate flaw in the argument of pro-Condorcet writers is they tend
not to return to basic normative principles that everyone can agree to-
perhaps one of the most important is the concept of irrelevant
alternatives, which I think was first utilised by Kenneth Arrow in his
classic "Social Choice and Individual Values"- that any loss of any number
of losers from an election would result in the same winners. My
understanding of "SC&IV" is that Arrow proves that if such a situation
exists for single-option ranking (or single-member voting) (where
obviously two candidate elections will be won by the candidate with the
simple majority of votes) then the social choice function (or election)
satisfying this will be the Condorcet ranking.

Interesting note- if you take the principle into proportional multi-member
eletions you can get some form of Condorcet rule with PR. Expect an e-mail
from me soon about "quota-Condorcet proportional election" (Geez, I know
you can't wait...)