[EM] Legal brief vs. San Francisco limited IRV
Dave Ketchum
davek at clarityconnect.com
Tue Mar 9 21:37:28 PST 2010
Views:
IRV needs rejecting, though I will not try to prove this here.
TTR is not the best to hope for.
Condorcet is good.
Asset is up to Abd ul to defend.
On Mar 9, 2010, at 9:42 PM, Abd ul-Rahman Lomax wrote:
> At 11:21 PM 3/7/2010, Kathy Dopp wrote:
>> On Sun, Mar 7, 2010 at 9:08 PM, Abd ul-Rahman Lomax <abd at lomaxdesign.com
>> > wrote:
>> > At 12:39 AM 3/7/2010, Kathy Dopp wrote:
>> >>
>> >> I've posted the latest plaintiffs' legal brief here. Plaintiffs
>> >> Francisco rank only three version of IRV.
>> >>
>> >> http://kathydopp.com/wordpress/?cat=8
>> >
>> > It is actually brilliant. Yes; limited. My view is that IRV is
>> generally
>> > constitutional. I.e., if top two runoff is constitutional, full-
>> ranking IRV
>> > is constitutional.
>>
>> Top-two allows *all* voters the opportunity to participate in the
>> final election of who will govern, so is IMO clearly more
>> constitutional than IRV which fails constitutionality in at least
>> three ways:
While TTR usually helps, it CANNOT allow a usable opportunity to those
voters who find both candidates offered unacceptable - the French had
this problem in a national election a few years ago..
While it will often offer one unacceptable plus one barely tolerable,
it can stumble down to two unacceptable:
25Fat
24Thin
23Na
22Nb
6Nc - a majority are for Normal, but cannot tolerate Fat or Thin.
>>
> First of all, there is no controversy over the constitutionality of
> TTR. There likewise is no controversy over the constitutionality of
> vote for one Plurality. And, except for some narrow exceptions,
> there is no finding that IRV is not constitutional anywhere, if full
> ranking is allowed. The instant case is over the constitutionality
> of IRV with only three explicit ranks allowed (and assumed bottom-
> ranking if the voter does not list the candidate).
>
>> 1. fails to allow all voters to participate in the final
>> decision-making process by excluding voters from the last round
Thinking ahead to Condorcet, neither it nor IRV would object to
permitting more ranks, provided a satisfactory ballot format could be
agreed to. From the other side, what true pain does the three rank
limit inflict on sane voters - even three ranks is much more voter
power than Plurality offers?
>
>
> That's correct. But if full ranking is allowed, the "exclusion" is
> debatable. I agree it's a problem, and so does Robert's Rules of
> Order. But, notice, the issue might be decided on general public
> policy grounds, i.e., does IRV make the situation worse for these
> possible excluded voters? If it doesn't, I can anticipate that the
> defendants might argue, and the court might agree, that the right of
> participation in the decision, over the situation with plurality, is
> enhanced, not reduced. Courts will not always decide on narrow
> technicalities.
>
> IRV is definitely problematic in many ways, but whether or not those
> rise to a constitutional issue is not so obvious. I do agree that
> there is an issue here, with twenty candidates and three ranks. With
> that many candidates and only three ranks, there are quite likely
> real voters who have been prevented from both voting sincerely (as
> promised) and participating in the final decision. Note that if
> there is a majority required, as the initiative pretended, there
> would be no problem. There would be a runoff, and the voter would
> then not be deprived. So the real source of the problem is that the
> method pretended to find majorities, in order to gain approval, but
> doesn't. The ballot information pamphlet promised that the winner
> "would still be required to gain a majority of votes," but did
> anyone notice that the provisions themselves removed the requirement
> for a majority?
>
> Not enough attention was paid by the plaintiff attorneys to this
> blatant deception of the voters in the initiative that implemented
> IRV. Of course, if they had left in the requirement for a majority,
> as they pretended still existed, then it would have become quickly
> visible that IRV was not avoiding most runoffs, since whenever
> runoffs were required, it is rare that the additional ranking found
> a majority, and this is a well-known behavior of IRV in Australia,
> in the places where full ranking is not obligatory. Australian
> voting systems experts consider using IRV without allowing full
> ranking to be insane. And I think they might question the use of IRV
> in a 20-candidate situation in any case! IRV works, sort of, with
> partisan elections, much less well with nonpartisan ones.
>
>> 2. fails to treat all voters' ballots equally, counting the 2nd and
>> lower rank choices of some, but not all, voters
>
> I agree that this is a problem, but its speculative that it will
> fly. Bucklin, of course, has no such problem, and can use the same 3-
> rank ballot as RCV, and, if a true majority is required, there is no
> penalty for declining to rank more than one candidate. Either a
> majority will be found that differs from your opinion, or you get to
> choose again in a runoff. It is also possible to use a full-ranking
> Bucklin ballot, and it remains fairly simple to count. If Bucklin is
> to be used as a plurality method, I'd say this would be required on
> the same principles as it is not being suggested that it's required
> for IRV. But I'd also allow equal ranking, it does no harm and
> reduces ballot spoilage, and is actually a more accurate vote if the
> voter has no significant preference between two candidates.
>
> (Equal ranking is already allowed, only it's restricted generally to
> bottom rank. The proposal is to allow it at all ranks. Classic
> Bucklin, Duluth variation, allowed equal ranking in third rank, the
> lowest approved rank. It required exclusive ranking in first and
> second rank, but I see no reason to require a voter who has no
> preference between two candidates to decide which one to support. If
> the voter is supporting one, it would clearly indicate that the
> voter also supports the other. And the analogy is to multiple
> conflicting ballot questions; the common rule is that, if both pass,
> the one with the most Yes votes prevails.)
>
>> 3. fails to provide voters with knowledge of the effect (positive or
>> negative) of their votes on the candidates they rank due to its
>> nonmonotonicity.
>
> Yes. With IRV, you can cause a candidate to lose if you vote for the
> candidate. For clarity, here is how it happens. Suppose there are
> three candidates, A, B, and C. Your favorite is A. Your vote for A
> could cause C to be dropped. So then it's between A and C. But the C
> voters prefer B, in their transfers, who beats A as a result.
> However, if you did not vote for A (and someone like you, or a coin
> toss does this), then B is dropped, and A wins over B.
>
> It gets complicated because not all voters will add additional
> votes. This is not the only problem, because of another effect,
> Center Squeeze, where a more strategic vote would be to skip over
> your favorite and vote first preference for the compromise candidate
> whom you prefer over the IRV winner.
>
> Voting sincerely in IRV seems safer, but can produce worse results,
> so bad that you'd have seen a better result if you stayed home and
> did not vote.
>
> And that appears to have actually happened in Burlington. If fewer
> Republicans had voted for Wright, and instead decided to support the
> compromise candidate that they clearly preferred from analysis of
> the ranked votes, they'd have produced that result.
>
>> Top-two runoff treats all voters equally, allows all voters to
>> participate, and allows all voters to cast a ballot with a positive
>> effect on a candidate's chances of winning, (I.e. voters know which
>> candidate they are helping to win each election.)
>
> Yes. The overall system still suffers from center squeeze, but it's
> possible to fix that. Use Bucklin in both rounds! And allow write-in
> votes in the runoff. Because of the use of Bucklin in the runoff,
> those preferring a compromise candidate can still make a choice
> between the primary winners. Theoretically optimal methods (in terms
> of decision quality) seek a majority and don't stop until they find
> one, but the only possibly practical method for public elections
> that could do this would be Asset Voting.
>
>> > They've hit on a technicality, the loss of equal
>> > treatment of voters if the voter can't rank enough candidates,
>> but as they
>> > point out, the deprivation of equal treatment can be quite small
>> and be
>> > unconstitutional.
>
> That's correct. But it must be very clear. I think they've shown it.
>>
...
>> The Condorcet method would still be easy to count in that case too
>> since an n x n matrix (where n = # candidates) would still work just
>> fine.
>
> Well, easy compared to what? Compared to IRV, yes. Compared to
> Plurality or Bucklin, no.
>
> Condorcet methods suffer from the same problem as afflicts many
> complex voting systems: it requires voters to have much more
> knowledge than is necessary to express a Favorite vote.
...
>
>> > From my analysis, IRV, however, would not find a majority in most
>> of the
>> > elections that went to instant runoff in San Francisco, and
>> Bucklin would
>> > find it it in maybe half. But Bucklin is far less expensive to
>> count, it's
>> > precinct summable, just count all the votes in each rank
>> (typically three
>> > ranks were used) and report them separately. They can then be added
>> > together.
>> >
We seem agreed as to IRV and Plurality.
Comparison with Bucklin deserves more thought, since both do ranking:
Condorcet permits equal ranking for all ranks - simpler rule for
voters than Bucklin. Its' counting is for a race between each pair of
candidates - A>B, A<B, and A=B do not care about magnitude of
difference in rank on inequality. Results are precinct summable into
an N*N matrix for any collection of ballots, with the matrices summable.
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