[EM] STV - the transferrable part is OK (fair), the sequential round elimination is not

[Raph Frank]

On Sat, Oct 31, 2009 at 4:17 PM, Kathy Dopp <kathy.dopp at gmail.com> wrote:
> I believe that you misunderstood what I was saying below. It is the
> relative *number* of candidates who run for office relative to the
> number of the voters they represent compared to the same ratio for all
> other candidates that determines whether or not STV achieves
> proportional representation. I.e. STV is subject to vote splitting or
> insufficient candidates running to represent any group of voters.

Vote splitting is not a major issue with PR-STV.   (it is also less of
an issue with IRV than it is with plurality).  There can be some
tactics required due to the fact that voters don't always vote based
on party.

If a party has 20%+ of the support in a 4 seater, it will get 1 seat.
(Assuming that the voters rank all the party's candidates as the top
ranks).

As for insufficient candidates, well if a party doesn't run enough
candidates, then it is their own fault.

It can be a problem where an incumbent doesn't want a 2nd candidate
from the party running, in case the 2nd candidate ends up winning a
seat.