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

[Kathy Dopp]

I agree that the Droop quota or some similar quota should try to be
satisfied. STV doesn't always satisfy it due to exhausted ballots.
Vote-splitting does mean less proportional representation using STV if
more candidates run relative to some groups' constituency share
compared to other groups.  That and all STV's other extreme flaws is
why any of the other better proportional systems are more proportional
and also better in a host of other ways.



On Sun, Nov 1, 2009 at 9:14 PM, Raph Frank <raphfrk at gmail.com> wrote:
> 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.
>



-- 

Kathy Dopp

Town of Colonie, NY 12304
phone 518-952-4030
cell 518-505-0220

http://utahcountvotes.org
http://electionmathematics.org
http://kathydopp.com/serendipity/

Realities Mar Instant Runoff Voting - 18 Flaws and 4 Benefits
http://electionmathematics.org/ucvAnalysis/US/RCV-IRV/InstantRunoffVotingFlaws.pdf

Voters Have Reason to Worry
http://utahcountvotes.org/UT/UtahCountVotes-ThadHall-Response.pdf

Checking election outcome accuracy --- Post-election audit sampling
http://electionmathematics.org/em-audits/US/PEAuditSamplingMethods.pdf