[EM] (no subject) STV transfer rules

[Jonathan Lundell]

On Nov 2, 2009, at 9:54 AM, James Gilmour wrote:

> robert bristow-johnson  > Sent: Monday, November 02, 2009 5:44 PM
>> whose *ballot* gets their vote transferred?  it shouldn't matter in
>> which order the counting is.  if my ballot is needed to give the
>> candidate what he needs, and your ballot isn't needed, then you got
>> to influence the election of your next choice, but I did not.  that
>> can't be fair.
>
> Opinions differ on the importance of this feature  -  as can be seen  
> from the continued acceptance in some jurisdictions of STV
> rules that treat ballots differently in this way.
>
> But if this feature is important in your assessment of "fairness",  
> then you could use either the WIGM (Weighted inclusive Gregory  
> Method) version of STV-PR as implemented for the Scottish Local  
> Government elections or Meek STV.  In both of these STV-PR versions  
> ALL of the candidate's ballots are transferred when any transfer of  
> votes has to be made.  Then there is no discrimination of the kind  
> you describe between these voters.

While Meek is preferable in this regard, even the random-transfer  
mechanism used by Cambridge MA is "fair" in the sense that all voters  
are treated equally--each has the same chance of having their ballot  
chosen for transfer, and with a sufficiently large election, the  
distribution is quite good.

Still, I don't think anybody implementing STV these days is likely to  
use that particular mechanism.