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

[Kathy Dopp]

Ralph,

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.

STV has all the same flaws of IRV and is hence unsuitable for use in
any elections. Its flaws far outweigh its benefits, esp given the
existence of methods that achieve proportional representation more
reliably and without causing all the other problems that STV causes.

Kathy

>
>> 3. STV does *not* achieve proportional representation at all unless
>> there is no vote splitting and just the right number of candidates run
>> who support each group's interests. I.e. the success of methods like
>> STV to achieve proportional representation rest in the unlikely
>> assumption that just the right proportion of candidates run (or more
>> precisely an equal proportion of candidates run) in proportion to the
>> number of voters in each separate group.  This is just simple
>> mathematical fact.
>
> Generally it does achieve reasonable proportional representation.
> Parties might get less than proportional in one constituency and more
> than proportionality in another, due to randomness.
>
> However, the smaller the constituencies the bigger the "seat bonus"
> given to larger parties.
>
> Again, the more seats per constituency, the better, as that gives
> better proportionality and makes it easier for smaller parties to get
> seats.
>

-- 

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