[EM] PR for USA or UK

[Jameson Quinn]

I agree that PRV would give better results, with sophisticated voters, than
most forms of PR. However, it does fail my criterion 4 (simple ballots) and
do worse than SODA-PR on criteria 5(smooth transition) and even arguably
1(true proportionality - because separate districts spoil the
proportionality). If you don't think these criteria are reasonable, you
should give that argument.

I started out with a list of criteria because I think that's the right place
to start when you're looking for a practical system.

JQ

2011/7/23 Toby Pereira <tdp201b at yahoo.co.uk>

> My preferred system of proportional representation is proportional range
> voting. Each voter gives the candidates a score and the result are
> calculated from this. I have my own system of PRV -
> http://www.tobypereira.co.uk/voting.html - which I prefer to Warren's
> Reweighted Range Voting for various reasons. Mine can also be converted to a
> sequential method if computing power deems it necessary.
>
> So we would have geographical constituencies with several seats available
> in each, and candidates would be elected accordingly. No need to vote for
> parties. You would purely be voting for the candidates in your geographical
> constituency.
>
> Why range voting? I make an argument here -
> http://www.tobypereira.co.uk/voting2.html - but I'll summarise. First of
> all, I think that the argument for range ballots over ranked ballots is
> (even) greater for PR than it is for single-winner elections. STV with
> ranked ballots assumes that you want to get your first choice elected over
> any number of your next preferences, and so only when that is settled, will
> your vote be used further down your preference list (if it still can be).
> 1st choice > 2nd + 3rd + 4th. But it's not as if it can make any other
> assumption either because that would be a guess too. Also there's Warren's
> example here - http://rangevoting.org/PRcond.html. By submitting a range
> ballot, you are indicating how much you like each candidate. Strategy aside,
> I would argue that a proportional form of range voting is probably the
> purest form of PR there is.
>
> So what about strategy? Would strategy ruin the "purity" of proportional
> range voting? I don't think it would too much. Unless the voters of some
> candidates are better at voting strategically than the voters of others,
> then I don't see it as too much of a problem. And no system would be
> entirely free from strategy. Specifically under PRV, people might vote down
> some of their preferences if they think it's likely they'll be elected
> anyway. It's a bit of a risk though, so I'm not sure it would happen too
> much. If we can trust Warren's Bayesian Regret figures for single-winner
> cases and range voting generally comes out on top there, I don't think it
> would be too much of a stretch to imagine that it might also come out on top
> for multiple winners.
>
> And I would argue that more "strategy-resistent" systems generally work by
> basically doing the strategy for you, so already give "dishonest" results.
> So it's not that they give better results. On my website I give an example
> where party A has 68% of the support and party B 32%. There are two seats
> and so each party fields two candidates. Assuming everyone would vote
> approval style, under my system, they would win one each. Party A would need
> over 75% of the votes to win the second seat. I would argue that this is a
> fair result (75% being bang in the middle between 50% and 100% - the amount
> to exactly earn one and two seats). Of course party A voters could
> coordinate themselves and split into two factions of 34% to take both seats,
> but this would be very hard for them to achieve. STV (Droop quota
> anyway) would transfer the votes above the quota accordingly so that party A
> would win both seats, and give what I would regard as the less fair result.
>
> By the way, I tend to think quotas, whether Droop or Hare, all end up being
> fairly arbitrary. Droop is supposed to be the "best" because it's supposedly
> set as low as possible, but in reality it isn't. It's not as if all
> elected candidates ever end up exactly on the quota so unless you have a
> moveable quota then it always ends up being too high and more votes could be
> transferred away.
>
> I'm probably not acquainted enough with SODA or SODA-PR to give a full
> argument against it, but generally I think that voters would regard the idea
> of giving their votes to candidates in a delegable manner as just too weird.
> I'm not sure people would really get the point of it and would just want to
> have their own ranked list of candidates instead (and as we know, ranking
> isn't as good as range!) I'm not sure it would give better result than PRV
> anyway, or even Proportional Approval Voting (again, my version of it), and
> I'd have PAV as my second choice if PRV was deemed too complicated. I don't
> think it is too complicated though. It's not any more complicated for the
> voter than STV, and scores can be out of a low number if need be. 6 would be
> fine.
>
>  ------------------------------
> *From:* Jameson Quinn <jameson.quinn at gmail.com>
> *To:* EM <election-methods at lists.electorama.com>
> *Sent:* Sat, 23 July, 2011 15:45:04
> *Subject:* [EM] PR for USA or UK
>
> We had a discussion about the best practical single-winner proposal, which,
> while it certainly wasn't as conclusive as I'd hoped, seemed productive to
> me. I think we should have a similar discussion about PR.
>
> Obviously, the situations in the UK and in the USA are very different in
> this regard. The UK is, as far as I know, the origin of the PR movement (in
> the 1860s and 1870s, liberals gained seats disproportionately as the
> franchise was extended, and Conservatives looked for a "fairer" system to
> recoup their losses). And it's part of Europe, where people have experience
> with PR. But both the UK and the US currently elect their principal
> representative bodies by district-based FPTP/plurality.
>
> And so I'd like to suggest that we should be looking for a PR system which
> satisfies the following criteria:
>
> 1. Truly proportional (of course). I would be willing to support a
> not-truly-proportional system, but I'm not everyone. Egregious compromises
> on this issue will simply reduce the activist base, to no benefit.
> 2. Includes a geographical aspect. People are attached to the "local
> representation" feature of FPTP, whether that's rational or not.
> 3. No "closed list". A party should not be able to completely shield any
> member from the voters. In general, voter power is preferable to party
> power, insofar as it's compatible with the next criterion.
> 4. Simple ballots. A reasonably-thorough voter should not have to mark more
> than, say, 5 candidates or options, and an average ballot should not list
> more than 20 candidates or options. Those are extreme limits; simpler is
> better, all the way down to around 7 options (of which only around half will
> be salient and/or viable).
> 5. Ideally, the smoothest transition possible. If existing single-winner
> districts can be used unchanged, all the better.
> 6. Insofar as it's compatible with the criteria above, greater freedom in
> voting is better. For instance, if ballots are printed with only in-district
> candidates, a system which allows out-of-district write-ins is better than
> one which doesn't, all other things being equal.
>
> My proposal for SODA-PR satisfies and surpasses all 5 criteria. Other
> systems which do reasonably well:
> -I've seen a proposal for single-member districts and open party lists.
> This is similar to my SODA-PR system, except that it requires that all
> candidates in a party approve the same party set. As such, it is strictly
> worse on criterion 3, without being notably better on any of the other
> criteria. It is more conventional, though.
> -Multimember districts, with some system inside each district.
> -Mixed member systems.
>
> Still, I would argue that SODA-PR sets a high water mark on all the
> criteria I mentioned, and is therefore the system to beat. I'm somewhat
> surprised that it hasn't gotten more comments. I'd especially like it if
> people could come up with clever mechanisms to (virtually) ensure
> that discarding whole ballots gives the same results as fractional ballot
> reweighting, using some probabilistic wording or process. (For instance:
> "When choosing seat N+1, select the previous N seats with random discarding
> until you get the same answer three times"... needs work I think. Or a proof
> that the fractional process is always the highest-probability result of the
> random-discard process - which I'm sure is very close to true, but not sure
> is true - so that you could write a statute to just say "highest-probability
> result".)
>
> JQ
>
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