[EM] STV and weighted positional methods

[Raph Frank]

On Sun, Feb 1, 2009 at 8:00 PM, Kathy Dopp <kathy.dopp at gmail.com> wrote:
> On Sun, Feb 1, 2009 at 12:58 PM, Raph Frank <raphfrk at gmail.com> wrote:
>
>>
>> But you are recommending that minority representation is dependent on
>> gerrymandering?
>
> Apparently you completely misunderstood what I said not once, but
> twice. Please reread what I said.
>

I assume you mean:

>>  But you're right that a single ranked or rated vote method
>> if a fair method (unlike IRV/STV) would better allow for a
>> geographically dispersed minority group to obtain
>> representation if they came out and voted in numbers
>> proportionate to their population for candidates who
>> represented their position and if their proportion of the
>> population were at least 1/N where N is the number of seats
>> being decided.

Ok, so that is single non transferable vote.  Each voter votes for 1
candidate and the N candidates with the most votes win the N seats?

This has serious strategy issues.

For example, lets say that there are 3 parties and 5 seats

A1: 25
A2: 20
A3: 10
B1: 15
B2: 12
C1: 18

The winners are
A1, A2, C1, B1, B2

The A party obtained 55% of the votes but only obtained 2 of the
seats.  PR-STV would have allowed transfers from A1 and A2 to A3 in
order that A3 would win a seat too.

For parties to win a proportional number of seats, they have to
coordinate their votes.  If the A party recommended that some voters
switch their support to A3, then the result might have been

A1: 20
A2: 19
A3: 16
B1: 15
B2: 12
C1: 18

The trick is to split your votes evenly between candidates.

However, if you overdo it, you might end up not winning any seats.

This means that the party leadership has to keep a tight reign on
their candidates.  Also, voters have to follow instructions in order
to optimise their votes.

The effect of this is to shift power from voters to the party leadership.

PR-STV handles the transfers automatically.  If you vote for a
candidate who turns out not to win, you vote is reassigned to another
candidate who has a chance of winning.  Likewise, if to many voters
vote for a candidate, then excess/surplus votes are reassigned.