[EM] Fractional STV for PR

[James Gilmour]

James Green-Armytage  > Sent: Sunday, August 29, 2004 10:07 AM
> 	However, surprisingly, the fractional transfer issue 
> doesn't end there. Note that in STV-PR, candidate 
> eliminations happen before surplus transfers.

James, where did you get this statement?  As written, it is wrong.  If you had written "candidate
eliminations CAN happen before surplus transfers", you would have been correct.  But then that would
have had a major bearing on your subsequent statements about tactical voting.  In elections with
small electorates these tactics are sometimes employed by "clever" voters who believe they can
predict the voting behaviour of most of the other voters sufficiently well to make such tactical
ploys worthwhile.  But in major public elections .....?

In all STV rules, significant surpluses, ie those can alter the order of the bottom two (or more)
candidates, must be transferred BEFORE any candidate can be eliminated.  It is only when there are
no surpluses or no significant surpluses that an elimination can occur before the transfer of a
surplus.

As James G-A said, the history of fractional transfer values is as old as the history of STV-PR
itself.  But there is more to this than simply some arithmetic.  There is a major difference in the
underlying philosophy of representation between those who want to retain integer transfers and those
who promote fractional transfers.  Integer transfer (the "exclusive" approach) is about maximising
the diversity of representation.  Fractional transfer (the "inclusive" approach) is about maximising
consensus in the selection of representatives.  Some of the arguments for fractional transfers
appear to be rooted in social choice theory.  Those who promote social choice consensus are
vigorously (and vehemently) opposed by those who promote the merits of maximising diversity.

These issues arose during the discussions on the Local Governance (Scotland) Bill in the Scottish
Parliament earlier this year.     Some of them are discussed in this Briefing Note (PDF file 42 KB):
http://homepages.phonecoop.coop/James.Gilmour/STVTransferRules.pdf

James