Comments on: London’s Mayoral elections: maxmising my voice by strategic use of preference voting http://jackthurston.com/london-elections-strategy/2008/04/18/ notes and articles by Jack Thurston Thu, 20 Nov 2008 08:52:24 +0000 http://wordpress.org/?v=2.5.1 By: Jon Worth http://jackthurston.com/london-elections-strategy/2008/04/18/#comment-1193 Jon Worth Tue, 22 Apr 2008 10:15:13 +0000 http://jackthurston.com/london-elections-using-your-second-preference/2008/04/18/#comment-1193 OK, good... :-) I've never been involved with the technicalities of an AV election, only STV elections, and there you have a variety of weights for the re-distributions (although they don't do that in Ireland). This explains it: http://pl.atyp.us/misc/votefaq.txt ---------------------------------------------------------------------- Single Transferable Vote (STV) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This is a system for electing multiple candidates in a constituency. Each voter marks '1' against the candidate they most like, '2' against their next favourite, and so on until they have no preference for the remaining candidates. The highest preferences for each candidate are counted. If any candidate has more votes than the Quota, they are elected. The Quota is calculated as: Quota = int(V/(N 1)) 1 where: V = number of votes N = number of candidates to be elected int() = convert to integer, rounding down The rationale for this formula is that the quota is the smallest number of votes such that the candidate is certain to be within the top N candidates. If someone is above the quota, the additional votes above the quota are reallocated to the other candidates according to the voters' lower preferences. This is done by giving each vote of the candidate a fractional value according to the fraction that the candidate was above the quota. (In Ireland they use the simpler, but less precise, system of simply picking a bunch of the candidate's ballot papers at random and using those for reallocation.) If no-one is above the quota, the candidate with the smallest number of votes is eliminated, and their votes are reallocated to other candidates. When votes are reallocated, if the voter has expressed no further lower preferences, their vote is discarded. This procedure is continued until all N candidates are elected. OK, good… :-)
I’ve never been involved with the technicalities of an AV election, only STV elections, and there you have a variety of weights for the re-distributions (although they don’t do that in Ireland).

This explains it:
http://pl.atyp.us/misc/votefaq.txt

———————————————————————-
Single Transferable Vote (STV)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is a system for electing multiple candidates in a constituency.
Each voter marks ‘1′ against the candidate they most like, ‘2′ against
their next favourite, and so on until they have no preference for the
remaining candidates.

The highest preferences for each candidate are counted. If any
candidate has more votes than the Quota, they are elected. The Quota
is calculated as:
Quota = int(V/(N 1)) 1

where:
V = number of votes
N = number of candidates to be elected
int() = convert to integer, rounding down

The rationale for this formula is that the quota is the smallest
number of votes such that the candidate is certain to be within
the top N candidates.

If someone is above the quota, the additional votes above the quota
are reallocated to the other candidates according to the voters’
lower preferences. This is done by giving each vote of the candidate
a fractional value according to the fraction that the candidate was
above the quota.

(In Ireland they use the simpler, but less precise, system of simply
picking a bunch of the candidate’s ballot papers at random and using
those for reallocation.)

If no-one is above the quota, the candidate with the smallest number
of votes is eliminated, and their votes are reallocated to other
candidates.

When votes are reallocated, if the voter has expressed no further
lower preferences, their vote is discarded.

This procedure is continued until all N candidates are elected.

]]> By: Jack Thurston http://jackthurston.com/london-elections-strategy/2008/04/18/#comment-1188 Jack Thurston Fri, 18 Apr 2008 11:46:13 +0000 http://jackthurston.com/london-elections-using-your-second-preference/2008/04/18/#comment-1188 Yes, in the second round there is no difference in weight between a first preference vote and a redistributed second preference vote. Fractional transfer is pretty rare, certainly for mass elections. I believe it is used more for elections with a rather smaller electorate (say a University board or such like). Yes, in the second round there is no difference in weight between a first preference vote and a redistributed second preference vote.

Fractional transfer is pretty rare, certainly for mass elections. I believe it is used more for elections with a rather smaller electorate (say a University board or such like).

]]> By: Jon Worth http://jackthurston.com/london-elections-strategy/2008/04/18/#comment-1187 Jon Worth Fri, 18 Apr 2008 11:24:25 +0000 http://jackthurston.com/london-elections-using-your-second-preference/2008/04/18/#comment-1187 Is the redistribution the transfer of a complete vote? You don't transfer fractions as in some STV systems? Is the redistribution the transfer of a complete vote? You don’t transfer fractions as in some STV systems?

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