[EM] Burlington VT reconsidering IRV 10 years after IRV failed to elect the Condorcet Winner

robert bristow-johnson rbj at audioimagination.com
Wed Dec 4 17:50:04 PST 2019

Lotsa people to respond to.  I feel I must begin with Markus because, as a signal processing algorithmist, I have so much respect for Markus and for the Schulze method.

I think I understand the Schulze beatpath method and agree with the consensus of the geeks that, technically, it is simply the best currently-known RCV method.  Most immune to all of these voting strategies.

But I consider cycles to be an extremely rare outcome of any Condorcet-compliant ranked choice system.  And, while it's uncommon (perhaps happened only with Burlington a decade ago) for an STV or Hare or whoever IRV to not elect the Condorcet winner, we found out that it can happen at least once.  Appears to be the only RCV election held by a government that did not elect the Condorcet winner, but my concern is that a voting system that does not always elect the Condorcet winner may become law again in the very city where this IRV failure occurred.

If I had my druthers, I would perhaps plug Ranked Pairs because RP will always elect the same winner as Schulze in the case of a Smith set of 3 or less.  A cycle in a governmental election will be rare, but a cycle involving more than 3 candidates happening in a governmental election is, I think, virtually astronomically unlikely.  Ranked Pairs is, for me, so much easier to describe than beatpaths. Markus, to be totally honest with you, I just don't think that Schulze has an ice-cube's chance in getting adopted for a governmental election. But maybe another, simpler-to-describe Condorcet-compliant method can.

So if I had my druthers, it would not be BTR-STV.  But here I am in Burlington Vermont of all places.  At least in this town, we should be aware of how election reform was set back a generation (assuming it takes another decade to finally get RCV to return to this 3-party town) when this IRV hiccup occurred a decade ago.  Now the Progs are actively trying to get the same-old IRV, repackaged as "RCV", but no different than what failed us in 2009.  They have already submitted language for how the question will appear on the ballot.  They sorta left this to the last minute to try to punch it through without argument to get on the ballot.  The city council must make the inclusion decision in 12 days. If they do not put the question on the ballot, it will delay the decision for a year, but charter change is also state law, so it will take another year to get enacted.  And they want this in place for the next mayoral election.  That's why the current push on this legislation.

My only hope and my only intention is to try to persuade some skeptical people in the Vermont Progressive Party that their submitted language can be changed without breaking RCV.  I know they will come back and say my language is too complicated and theirs is simpler.  I will tell them that theirs is simpler and wrong and point out exactly why in what happened in 2009 (I can post that letter to the list, if people are interested in how I do politiking).  But I want to show them language that is the least amount of change from their language, but will result in a Condorcet-compliant method.

I will feel like I succeeded and gained something if **any** Condorcet-compliant RCV method is adopted, but if they don't change the language, I will hold my nose and still support the old, crappy IRV, if that is what gets on the ballot.  That would be better than electing Mayor 41% and that is what we are potentially in danger of now.

So I can't have Schulze, I can't have Tideman, I can't have FAB-STV (and I don't think that Richard's 4a, 4b, 4c is an improvement), I can't have Instant Pairwise Elimination.  I can't expect to, in 5 days, walk into the room where the Charter Change Committee meets and tell them to totally replace their entire language with something completely different (except for the ranked ballot).  The best I can hope for is language that changes how the candidate is eliminated in STV, so that the Condorcet winner is never eliminated.  That's what BTR-STV is good for; it is a political increment (when RCV becomes Condorcet-compliant) and sometimes increments in reform is all we can hope for.

So, for reasons of political practicality, it's gotta be BTR-STV or it goes back to Hare STV.  And that will also be a fight.  RCV might lose in either case and we continue with FPTP with 40% minimum.  But also a bad outcome would be if the same IRV was returned to statute and we had another failure like we had in 2009.  Then voting reform will be set back for a lot more than a generation.  At least if we can get an IRV that is Condorcized, we won't have a repeat of 2009 and the repeal that happened the year after.

So the only thing that helps is good, concise language for BTR-STV that retains the form of the original language that I posted, has one part that is different, and I get to defend that one part that is different.  That's all I can get away with.

Thanks, y'all for your attention and comments.  So far, I am sticking with my language, but I can be convinced that some other is better, if the suggestion comes from understanding what political and time constraints I have at the moment.



> On December 4, 2019 3:06 PM Markus Schulze <markus.schulze8 at gmail.com> wrote:
> Dear Robert Bristow-Johnson,
> the best possible election method according to the
> underlying heuristic of instant-runoff voting will
> always be instant-runoff voting. Therefore, I don't
> think that any supporter of instant-runoff voting
> will be convinced by a hybrid of Condorcet voting
> and instant-runoff voting.
> Bottom-two runoff violates monotonicity and reversal
> symmetry. Therefore, when you promote bottom-two
> runoff, you cannot use these criteria against
> instant-runoff voting.
> Bottom-two runoff violates independence of clones
> while instant-runoff voting satisfies independence
> of clones. Therefore, this criterion will be used
> against bottom-two runoff.
> When you promote bottom-two runoff and fail to
> convince the audience about the importance of the
> Condorcet criterion, you don't have any arguments
> anymore against instant-runoff.
> I strongly recommend that you should promote the
> Schulze method because of the following reasons:
> (1) The Schulze method satisfies not only the
> Condorcet criterion, but also monotonicity,
> reversal symmetry, independence of clones and many
> other criteria. Therefore, the Schulze method is a
> very good method even when there is no Condorcet
> winner or when you fail to convince the audience
> about the importance of the Condorcet criterion.
> (2) The Schulze method is currently the most
> wide-spread Condorcet method.
> (3) The Schulze method has been published in an
> important peer-reviewed journal:
>     Markus Schulze, "A new monotonic, clone-independent,
>     reversal symmetric, and Condorcet-consistent
>     single-winner election method", Social Choice and
>     Welfare, volume 36, issue 2, pages 267-303, 2011,
>     DOI: 10.1007/s00355-010-0475-4
> Here are some useful links:
> https://en.wikipedia.org/wiki/Schulze_method
> https://www.ourcommons.ca/Content/Committee/421/ERRE/Brief/BR8397842/br-external/SchulzeMarkus-e.pdf
> Markus Schulze
> ----
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r b-j                  rbj at audioimagination.com
"Imagination is more important than knowledge."

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