RCV IRV Hare
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It's important that we set ourselves and society up for success the first time,
Totally agreed---that's why I think we should be data driven and pass reforms that have a measurable impact. I find quality research studies to be much more compelling than speculation.
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@andy-dienes said in IRV:
@sass said in IRV:
It's important that we set ourselves and society up for success the first time,
And I'll add to what Andy said, I think that approach sounds nice but it may be unrealistically idealistic.
In the US, the "first time" might be the Constitution, ratified 234 years ago. It had compromises like considering some people to count as 3/5ths of other people. (and those "lesser" people weren't allowed to vote). They did what they had to do to move forward. While that example is a pretty extreme one, there are a huge number of things that people wisely compromised on so that they could make progress.
Most of the places we can get a new election method implemented have already had their "first time", which was choose-one plurality. Moving them to RCV-Hare is a whole lot easier than moving them to RCV-something-that-no-one-has-tried-yet. Regardless, it won't be their first time.
I'm all for putting better methods out there as options. In fact, I would love to see some Condorcet advocates put together a proposal for, say, San Francisco, where it would be a small step forward from the RCV-Hare that has been used here for 17 years.
I'm also all for us putting our argument that Condorcet is better than IRV to FairVote, but in a way that allows them to keep calling it RCV, and allows them to allow potential new "clients" (i.e. governments that are considering adopting RCV) to pick whichever one they are comfortable with.
The funny thing about this (well, ironic, rather than haha funny) is that we, of all people, should be advocates for compromise approaches rather than "my way or the highway".
But going back to the whole "evidence" thing.... I haven't seen evidence that IRV-Hare does any of these bad things that you speculate that it will.
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I'm also all for us putting our argument that Condorcet is better than IRV to FairVote, but in a way that allows them to keep calling it RCV, and allows them to allow potential new "clients" (i.e. governments that are considering adopting RCV) to pick whichever one they are comfortable with.
Well, I didn't argue for it, but I asked "FairVote" their opinion of RCV IRV bottom-two runoff, on Twitter. And to my surprise, they responded.
Approval-ordered Llull (letter grades) [10], Score // Llull [9], Score, STAR, Approval, other rated Condorcet [8]; equal-ranked Condorcet [4]; strictly-ranked Condorcet [3]; everything else [0].
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two competitive factions,
Are you talking about factions among the candidates, or factions among the voters?
not a race to 50%+1.
That's an absolute majority. Is there any seriously-proposed system that won't elect a candidate who has majority support (as their first choice), provided that the majority knows they are the majority and chooses their strategy in a way that takes that into account and is aimed at winning?
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@jack-waugh Interesting that you got a response.
They say "IRV & bottom-2 runoff will usually have the same result but different campaign incentives. IRV rewards those w/ strong 1st choice support. Bottom-2 rewards those who avoid polarizing stances. We like IRV since it encourages real stances, not just campaigning to avoid the bottom"
It's really odd for them to claim that people would campaign differently when both methods "usually have the same result." If they have the same result in 339 out of 440 elections (which they proudly proclaim in multiple articles).... why would campaign incentives be so different?
Also odd that what they are arguing here seems to be the exact opposite of what they argue elsewhere. They are basically saying "Polarization is bad. Our voting system is better than others, because ours doesn't polarize people like those other systems do. Except, the reason we're better than Condorcet compliant systems, is that those systems have the exact same effect of reducing polarization.... but they do it even more than we do, and that's probably just too much".
I don't see how that makes sense. They really are talking out of two sides of their mouths.
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@rob so I suggest you respond to them on Twitter.
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@Sass, it's almost time for the realtime discussion that you regularly host. I intend to use the opportunity to put the following questions to you.
I have a question or two arising from what you and Rob B. have been saying back and forth. You distinguish the historical votes in the US where we have better ballot data than just what Choose-one Voting gives, as to whether they involved competition among more than two factions. Are those factions among the candidates, or factions among the voters? And how do you discern whether such factions existed for a given one of those elections?
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@rob said in RCV IRV Hare:
I particularly like this chart showing how the IRV election for London Breed played out:
[]
It is interesting in that it makes clear certain things that aren't so clear in other ways of expressing results, including Condorcet matrices.... for instance it clearly shows how most of Jane Kim's votes went to Mark Leno. It is clear that Mark Leno would have done a lot worse in a plurality race, as Jane Kim would have been a spoiler.
You can do the same Sankey diagrams for Condorcet methods that eliminate candidates in rounds, like Baldwin's method or BTR-IRV.
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@rob said in RCV IRV Hare:
Yes this is true. 440 elections, all had a Condorcet winner. One of them didn't pick that Condorcet winner.
Where is the data for this?
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@psephomancy Are you looking for more than the statement from FairVote?
Here is where they say it: https://www.fairvote.org/research_rcvwinners
As for the ballot data for those 440 elections, I don't have it, but someone may. @Andy-Dienes , did you say you had parsed a ton of data? Personally I think we should convert as much as we can to a standardized format and make them available on this site. (with javascript versions of them, since that would allow easy linking them into CodePens etc.... see https://codepen.io/sergelerner/pen/dXdqPe )
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@rob said in RCV IRV Hare:
@psephomancy Are you looking for more than the statement from FairVote?
Here is where they say it: https://www.fairvote.org/research_rcvwinners
As for the ballot data for those 440 elections, I don't have it, but someone may.
Yeah, I've heard this claim a bunch of times but never with actual data showing that there was a Condorcet winner and that they won.
Of the 440 single-winner RCV elections in the United States since 2004 in which we have sufficient ballot data to assess whether the Condorcet winner won the election, all but one — the 2009 mayoral election in Burlington, Vermont — were won by the Condorcet winner.
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@psephomancy I remember we had a discussion a bit back where this was brought up. We all know about Burlington. But I think the general consensus is that FairVote isn't lying about this straightforward fact. If there was an election where it didn't pick the Condorcet winner, and the ballot data was published, I suspect that we'd know about it.
My understanding is that for all the Bay Area RCV elections there is full ballot data published. https://www.fairvote.org/every_rcv_election_in_the_bay_area_so_far_has_produced_condorcet_winners
Is there a reason you have to suspect that they aren't telling the truth, or that there might be a significant number of elections where ballot data isn't available but Condorcet winner didn't get elected? Just curious. It's not something I personally would be worried about.
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@rob I've seen the claim made many times, but never with any evidence to back it up, so I would like to know what the actual data is, and if it shows anything actually interesting.
If 90% of those elections had only one candidate, for instance, it wouldn't be particularly meaningful that RCV selected them.
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@psephomancy said in RCV IRV Hare:
If 90% of those elections had only one candidate, for instance, it wouldn't be particularly meaningful that RCV selected them.
It is true that the vast majority of elections have an "obvious" winner (aka true majority of first-preference votes) and many only have two or maybe even one real candidate(s).
Although I will say I can corroborate the claim that no IRV election (besides obviously Burlington) seems to fail Condorcet at least for the elections in San Francisco and Minneapolis, which were the ones I could find ballot data for.
While FairVote's editorials can be a little over-exaggerated and their terminology purposefully vague (never defining 'majority'), sometimes to the point of untruthfulness---they are a political advocacy group after all---I have never seen reason to question the basic facts they present.
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Over years, I've continually said that misrepresenting IRV is worse than IRV itself. I don't support IRV, but I can tolerate it if advocates somehow promote it without false statements. However, a system that is almost impossible to clearly discuss with lay people without false statements is a problem of the system itself.
On that same page where Fairvote talks about Condorcet and such:
It may be disputed whether it would have been better for Montroll to win the election despite attracting so little core support. However, it is certain that Montroll would have also lost under a two-round runoff election or a single-choice plurality election.
This is plainly wrong. Under a plurality election, we know with certainty that voters will be strategic, and that is why Montroll would have won. Their wording is missing the key point, and can be true only with this change:
it is certain that Montroll would have also lost under a two-round runoff election or a single-choice plurality election — if the voters were all completely honest, which we know plurality voting not to be.
Fairvote in this argument is trying to assert that IRV cannot be worse than single-choice plurality. They assert that by selectively ignoring the entire issue of strategic voting, even though they focus elsewhere on strategic voting. Fairvote is a model for motivated reasoning over fair reasoning.
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Given the preference data available, I think it is a very reasonable expectation that Montroll would not have won with either choose-one or top-two-runoff. Granted, I wouldn't go so far as to call it "certain," but it's surely reasonable.
Generally speaking, voters behave the way that candidates and parties tell them to. If all three candidates had stayed in the race, then they are signalling to voters "hey, you should still vote for me," and I don't think there's any reason to believe that voters' would change their first-preference behavior given how competitive the race was.
More likely, under choose-one, one of Montroll or Kiss would have dropped out of the race before election day; strategy will occur, but it typically manifests as candidate exit rather than voter behavior.
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@wolftune said in RCV IRV Hare:
and that is why Montroll would have won
Isn't stating that with such certainty doing pretty much the same thing as FairVote stating the opposite with such certainty?
We don't know what would have happened under choose-one plurality. We don't even know if Montroll would have run, maybe the Democrats would have run a candidate that was less centrist.
I agree that FairVote being disingenuous is a problem, but I do wish people wouldn't use that alone to bash (or otherwise lessen their enthusiasm for) positive change.
(My opinion on IRV is increasingly "it's doing the right thing, it just isn't doing it enough." Basically, it is pulling its punches.)
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Yeah. Everyone, including Fairvote, emphasizes that electoral systems change campaign behavior and voting behavior. There is no realistic scenario in which you change voting systems and all other behavior in the system stays. Discussing that artificial situation is only useful as a conceptual exercise in comparing some particular point in the math or something, not as an assertion about counterfactual situations.
There's no possibility that single-choice plurality voting in Burlington 2009 would have this 3-way race as it was. All the media and voters and everyone (candidates included) would have come to some pre-election idea of Montroll or Kiss as the primary non-Republican and the other as dangerous spoiler. They would have had that argument. And the result would be likely Montroll winning but maybe Kiss or even the Republican and then all the spoiler-blame fall-out. There's NO chance it would have avoided all those well-known dynamics.
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@wolftune we are in complete agreement here.
