[EM] PRfavoringracialminorities

[Raph Frank]

On Sun, Aug 24, 2008 at 10:44 PM, Kristofer Munsterhjelm
<km-elmet at broadpark.no> wrote:
> There are some limits to the transformation: for instance, you can't have
> representation below 1/(assembly size), thus the "power constraint" caveat
> of the transformation. Similarly, power is in steps of 1/(assembly size),
> and you can't have a sum power (over all representatives) higher than 1
> (which is to say, the assembly can't hold more reps than its size).

Right, it could work as

1) Voter votes for one party + maybe other info
2) Assign seats using d'Hondt's method
3) Eliminate any party with fewer than 2 seats
4) If any eliminated, redistribute votes of eliminated parties and goto 2)

The redistribution could be ballot based (voters rank the parties) or
party based (parties rank the parties prior to the election).

The method for deciding how the seats should be assigned in the party
is another issue.

I set the threshold at 2 as this reduces the effects of the
Webster/d'Hondt choice.  Maybe the final distribution should use
Webster's.

> But if it's true that a simple "FPTP then pick the n best" is a bad system
> for electing representatives with different power, and I'm right about the
> transformation, then it follows that ordinary list PR (which is just a FPTP
> vote for parties) can be a bad system as well.

Right.  Votes for parties that don't hit the threshold (5-10% in some
countries) are effectively thrown away.  It is surprising that a
bigger issue isn't made of this.

I guess people do complain about thresholds, but never about the risk
it poses to the voter.  If your party has 5% support and the threshold
is 5%, then there is a risk of throwing your vote away if you vote for
that party.

> If constituencies are too small and there's no national compensation, then
> list PR could suffer from the same problems as exist with FPTP applied to
> candidates: vote splitting and the familiar "worst of many evils" situation.
> Party list PR elections usually lead to multiparty democracy, though, so I
> am guessing that this effect isn't significant for real world party list
> districts. It can still be annoying, in particular to voters who are
> dissatisfied with existing parties but know that voting for a new party is
> "just throwing one's vote away".

If there are transfers, then this should be less of an issue.

If there are small constituencies, then PR-STV is a better choice.

> Again, it's not this simple in reality, but it's a good approximation. Some
> countries that have FPTP in single-winner districts have managed to keep
> multiple parties alive (India is an example, I think), and some of this can
> be attributed to regional differences where a party may be significantly
> stronger than its national share in some areas of the country, thus saving
> it from extinction of going below k%.

However, it is probably still 2-party for each individual constituency.

>> Voters would be recommended to vote for a candidate who is likely
>> to get elected as their 2nd choice.
>
> I seem to remember past posts on this list about so-called "three slot
> methods" that would have only two ranks, but approval-like ordering within
> each rank.

You mean equal ranks allowed ?

> Condorcet could also be used as a weighted-power method, but only if it
> gives scores and not just ranking for its social ordering. Perhaps an
> eigenvector method?

Not sure how you would work that.  Do you still mean that voters would
rank the parties?

What about something like PR-STV instead of a divisor method

1) Count votes
2) If party with most votes exceeds quota
- assign additional seat to party
- Remove one quota of vote from party (Remove random ballots or just
do normal PR-STV reweighting)
3) If no party is above quota, eliminate party with fewest votes and
reassign them to other parties
4) Goto 1) until all seats assigned to some party

I am not sure if the elimination rule is fair.  Maybe it should be
eliminate the party with the fewest seats and use currently held
points as tie break.  However, that is biased towards big parties.