[EM] IRV ballot pile count (proof of closed form)
Dave Ketchum
davek at clarityconnect.com
Wed Feb 10 10:08:24 PST 2010
Perhaps we have spent enough time plotting how to best count ballots
in IRV, while some note that the best planning is actually how to get
away from IRV:
Plurality - a reminder that we need to move ahead.
Condorcet - my preference, partly for moving ahead and partly
for accepting votes ala IRV.
Bucklin and other variants of Condorcet. Rules for these make
them more complex than Condorcet - I see their rules making them less
desirable.
Range - I see this as competitive with Condorcet, with valid
arguments for claiming either is better.
Asset - Abd ul likes. I doubt that the rest of us have looked
close enough to judge its merits.
Approval - true step up from Plurality; questionable whether it
is competitive with any others above.
Any other that let voters indicate which is/are best liked, best
liked of remainder; etc.
Condorcet does an N*N matrix showing for EACH pair of candidates which
is better liked - used in counting and usable by others to help plan
their future. Often there is a CW which wins for winning in all of
its pairs; else a cycle in which each would be CW if other cycle
members were not candidates.
How best to resolve a cycle is debatable, but a simple method
could be used unless others are demonstrated to be much better:
Delete weakest pair used to define the cycle; repeat until remainder
defines a CW.
Note that N*Ns show progress, or lack of such, among non-winners.
On Feb 10, 2010, at 5:33 AM, Kristofer Munsterhjelm wrote:
> Abd ul-Rahman Lomax wrote:
>> At 12:20 PM 2/8/2010, Kristofer Munsterhjelm wrote:
>>> Abd ul-Rahman Lomax wrote:
>>>
>>>> Given that much better methods exist, have been tried and worked,
>>>> and are much easier to canvass, WTF?
>>>
>>> If I were to guess: in part a desire to produce a stepping stone
>>> to STV, and in part organizational inertia. FairVote bet on IRV
>>> and now will "stay the course".
>> That's right. One of my first observations on this, when I became
>> aware of the election methods list and the Approval voting list,
>> and discovered the Center for Voting and Democracy, which had
>> started as the Center for Proportional Representation, and which
>> became FairVote, was that people trying to reform democracy didn't
>> trust democracy, they would always gravitate toward nondemocratic
>> institutions which are easily co-opted to become self-preserving
>> and inflexible. Typical co-opt is by staff!
>
> "Who says organization, says oligarchy". One has to be careful not
> to have the organization become undemocratic, because the default
> tendency is for it to turn so, since it is (initially) more
> effective that way.
>
>> Yes, it's quite likely that they will stay this course right into
>> the ground. Hitching proportional representation (a very good idea)
>> on to single-winner STV (a quite bad idea) may have seemed like a
>> good idea at the time, perhaps because of the "brilliant" invention
>> of the name, "instant runoff voting," which itself suggested a
>> strategy to spread the idea by attacking a vulnerable institution,
>> but it was, in fact, not sustainable.
>> Some of the reasons why it is not sustainable were not necessarily
>> known then. Who would have expected that IRV would closely imitate
>> Plurality in nonpartisan elections? Lots of people seem to be
>> surprised that IRV doesn't produce real majorities, but that one
>> was known.
>
> I think there's somewhat of an "improvement no matter how small"
> aspect to it, as well. "IRV handles the spoiler problem with minor
> third parties, woo hoo!" and then they stop there. But how much of
> that is after-the-fact justification (means for the ends that is
> STV) and how much of that is truly believed is hard to tell.
>
>> And the prior history of IRV in the U.S. should have been a clue.
>> What was it replaced with? Often -- not always -- with top two
>> runoff. Because of the desire for majorities....
>
> For multiwinner STV, you could argue that the reason it was replaced
> was not because it did so badly, but because it did too well.
> Consider New York. After STV, there were many parties, not just the
> Democratic stranglehold. What did the Democrats do, seeing their
> power being diluted? Since they didn't want to share, they started
> employing red-scare tactics, with such rational appeals as calling
> the method "Stalin Frankenstein".
>
> As for IRV, the single-winner method, you're probably right. In some
> situations, the reason is that it seems to provide no different
> results than Plurality. In others, there's complexity (which is made
> no better by that IRV isn't summable).
>
>>> To address the former: the grail here would be a polytime monotone
>>> summable multiwinner method that reduces to a good Condorcet
>>> variant (or Bucklin/Range/etc) in the single-winner case. A
>>> multiwinner method can be summable in two ways: summable with the
>>> number of seats held fixed, or summable no matter what.
>> Well, Asset bypasses the whole shebang, by making what we think of
>> as "elections" irrelevant. At least in theory. Everyone wins in an
>> Asset election, or, if not, then there is someone very specific for
>> the voter to blame: the candidate the voter voted for in first
>> preference. (Asset may be STV with the Asset tweak for exhausted
>> ballots, or it could just be vote-for-one. I, personally, would see
>> no need or desirability to rank more candidates, provided my choice
>> has a backup (a proxy should be allowed in case of incapacity), but
>> some people seem to think otherwise. I'd rather not yank my vote
>> away from my most-trusted candidate to put it in the hands of this
>> less-trusted candidate, but then to return it to the most trusted
>> if the less-trusted drops out somehow. .... rules in STV/Asset have
>> not much been delineated.)
>
> Dissolving the problem - making it irrelevant - is the best
> solution, when it can be done, yes. However, I feel unsure about
> Asset because it hands power to someone who may hand power to
> someone who may ... and so on. The closest thing to it around in
> governmental elections is where parties (or candidates) specify an
> inheritance order, and your vote follows that order; what results is
> that the candidates might transfer your vote in the wrong direction.
> For instance, if you vote for X because of Y, and X also likes some
> property Z that you don't, then if he transfers to Z, that is not
> what you want. Asset's logic is that you don't have to do that
> (because you can vote for a minor player and your vote will still
> not be wasted), but why doesn't that logic hold for vote inheritance
> orders? It seems like it would, yet we see the effect mentioned
> above...
>
> The iterated variant (some times called "liquid democracy") has
> another problem: the graph (who is a delegate of whom) is
> transparent - therefore, vote buying and selling becomes very
> simple. Now you may say that the voters won't accept a candidate who
> sells his power and so will desert the candidate, but as long as
> there's inertia (and reality seems to support that), the problem
> remains.
>
> If I were to dissolve the problem of elections, I'd rather look
> towards Gohlke's triad idea, or a larger PR variant. If the base
> layers have some measure of randomization, it becomes hard to
> influence the candidates ahead of time, because everyone (who's
> interested) is a potential candidate.
>
>>> What's important is that we don't know of such a method; but also
>>> that the stepping stone strategy itself might be dangerous - if
>>> the base method is bad, then it may fail to dislodge those whose
>>> interest is in less democracy, and so the objective of moving to
>>> multiwinner never gains any additional strength by the so-called
>>> stepping stone.
>> My own decision about all this is that it's best to begin with
>> NGOs, voluntary organizations that demonstrate how advanced methods
>> work. The Election Science Foundation held an Asset election for
>> its steering committee. It was quite interesting....
>
> Would the various (smaller, usually technical) organizations and
> groups using Schulze count in this direction?
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