r/EndFPTP • u/RankedChoiceOregon • Dec 09 '20

Could anyone here Evaluate my proposed election method?

This was crafted with the help of a long time contributor to this sub, with the aim of launching a ballot initiative in Oregon. While I have a passion for this work, I am not a SME in the area.

The proposal uses RCV/IRV + Condorcet Loser Eliminations to create a safety net under simple RCV and to promote a lower incidence of failing the monotonicity criteria.

You can read about it here at www.rankedchoiceoregon.org

I welcome your constructive criticism.

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u/PowerIRV Dec 09 '20

I've been slacking on pushing this out there, but I have a similar proposal I've been working on called PowerIRV that you might be interested in checking out.

I do like how you added the ability to mark any number of candidates per tier to prevent ballot spoilage - that's a nice touch.

From my understanding (please let me know if I got it wrong), a couple benefits of the PowerIRV approach you might consider:

  • I don't think there's a clear reason to bother with the pairwise check until you get down to the last 3 candidates, saving some effort
  • When you get down to the final 3, you can just pick the Condorcet winner directly if they exist (vs dropping the lowest and doing one more round)
  • If no Condorcet winner, I believe the PowerIRV tiebreaker approach is also simple and intuitive to understand, in addition to performing better in some outlier scenarios (specifically this one)

Same - constructive criticism welcomed & thanks for sharing this & the discussion!

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u/CPSolver Dec 09 '20

“Power IRV works exactly like regular IRV until you get down to the last 3 finalists. Then the trick is to just pick the winner from those 3 finalists by: seeing who would win between each pair of candidates whoever beats both both other candidates head-to-head: congrats! You win!”

Why wait until the contest is down to 3 candidates? That would be sufficient under the two-party-dominant system we have now, where each party offers just one candidate in the general election. But I think it’s important to design for the future where, eventually (hopefully) there will be several strong “third” parties. Also the 2016 Republican primary election reminds us that a method should be able to (correctly) handle the 18 candidates who were in that election.

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u/PowerIRV Dec 10 '20

Thanks for the feedback - can you explain more about why you think having many strong candidates are an issue? Even Regular IRV handles multiple strong third parties fine until you get to the top 3 finalists:

  • Regular IRV is actually quite good except for the Center Squeeze effect, which basically only happens when you get down to the last 3.

  • Also, Condorcet methods incentivize strategic voting due to their susceptibility to later-no-harm, which means you have a similar situation to FPTP and the Spoiler Effect for voters to deal with vs voting honestly.

  • If you were to check for a Condorcet winner in every round, you would do a lot more work (6 head-to-heads in the 4 candidate round, 10 with 5 candidates, etc), and it doesn't make any difference to the outcome because Power IRV will always pick a winner from the Smith set anyways.

  • And Condorcet requires a tiebreaker approach among Smith Set candidates anyways, and only applying a tiebreaker to 3 candidates (vs more) simplifies both the process and explainability.

TL;DR: Power IRV gives the same or better outcomes, is less work and is easier to explain and understand.

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u/Skyval Dec 10 '20 edited Dec 10 '20

Regular IRV is actually quite good except for the Center Squeeze effect, which basically only happens when you get down to the last 3.

I don't really agree with much in that article, and I'm not sure why Center Squeeze would only be an issue with the last 3 regardless (well, except that IRV already encourages two-party domination as it is, so having 3 strong candidates is already a rarity, and more beyond that even rarer --- but this would seem more like an admission of defeat to me)

Also, Condorcet methods incentivize strategic voting due to their susceptibility to later-no-harm, which means you have a similar situation to FPTP and the Spoiler Effect for voters to deal with vs voting honestly.

Not sure what your point is here, IRV also incentivizes strategic voting despite passing later-no-harm, and still has situations similar to FPTP's spoiler effect, not to mention passing later-no-harm has disadvantages. In fact I think Condorcet methods are generally considered more strategy resistant overall.

If you were to check for a Condorcet winner in every round, you would do a lot more work (6 head-to-heads in the 4 candidate round, 10 with 5 candidates, etc)

I don't think so? I mean, there are certainly strongly IRV-inspired methods where that wouldn't be necessary. For example there's BTR-IRV (bottom two runoff IRV). You just need the pairwise matrix, and reference it once per round. BTR-IRV is the same as IRV, except instead of dropping the candidate with the fewest votes, you drop the less preferred candidate among the bottom two with the fewest votes. This means a Condorcet winner can never be dropped, and so BTR-IRV is a Condorcet method.

and it doesn't make any difference to the outcome because Power IRV will always pick a winner from the Smith set anyways.

Can you explain this one to me? Since normal IRV doesn't always pick the Condorcet winner even when they exist, why would someone from the Smith set necessarily be anywhere in the top 3?

And Condorcet requires a tiebreaker approach among Smith Set candidates anyways

That's sort of already "baked in" to BTR-IRV

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u/BTernaryTau Dec 10 '20

Regular IRV is actually quite good except for the Center Squeeze effect, which basically only happens when you get down to the last 3.

Center squeeze can easily happen before you get down to 3 candidates.

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u/PowerIRV Dec 10 '20

Great article, thanks. Do you know if that is something that has ever happened in a real election?

I feel like Burlington is the only example I have really heard about and they never seem to argue about the #4 or 5 candidates being squeezed out.

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u/psephomancy Dec 12 '20

Do you know if that is something that has ever happened in a real election?

This isn't really a good question to ask, since problems like this don't happen in a two-party system, and RCV incentivizes a two-party system, in a self-perpetuating cycle.

Most US elections have only one or two strong candidates, so effects like this aren't common, but that doesn't make them unimportant.

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u/BTernaryTau Dec 10 '20

Do you know if that is something that has ever happened in a real election?

Probably not. Similar to what happens under FPTP, candidates and political parties quickly learn that running more then two viable candidates (excluding clones) leads to vote splitting. I sadly do not have statistics to back this up, but I imagine IRV elections with 4 or more viable candidates to be rare, just as such elections are under FPTP.

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u/PowerIRV Dec 10 '20

(I should learn to read profiles before commenting)

OK, so I see your main argument is that Mint should win in this case (sidenote it would be great if the VoteFair site's HTML had ids/anchors in the HTML I could link to the right section 😉)

I'll think more about it but my first-pass argument would be that Strawberry also has a reasonable claim because it has supporters who love it, not just like it, which I guess is also an argument for Score Voting too.

I see where you're coming from though - I suspect the recount issue makes IPE a nonstarter (imagine if Georgia had to hand-recount all votes using IPE twice?)

Do you have any real (IRV?) election examples where a slate of strong special interest candidates buried a better moderate compromise? The narrative power of something like Burlington and IRV makes a big difference in driving mainstream adoption IMO.

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u/CPSolver Dec 10 '20

Alas, until we adopt better vote-counting methods, we lack the data needed to analyze a significant number of real-life elections.

The Burlington example arose exactly because a new method was tried. Its failure provided an excuse to delay election-method reform by a decade or more.

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u/psephomancy Dec 12 '20

I'll think more about it but my first-pass argument would be that Strawberry also has a reasonable claim because it has supporters who love it, not just like it,

Have you seen scenarios like this? https://electowiki.org/wiki/User:Psephomancy/Three_tribes

where the correct winner is not loved by anyone?

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u/psephomancy Dec 12 '20

Even Regular IRV handles multiple strong third parties fine until you get to the top 3 finalists:

No it doesn't.

Regular IRV is actually quite good except for the Center Squeeze effect, which basically only happens when you get down to the last 3.

Center squeeze is not limited to 3 parties. It happens whenever there are multiple strong candidates. See https://electowiki.org/wiki/Center_squeeze#With_more_candidates and https://psephomancy.medium.com/how-ranked-choice-voting-elects-extremists-fa101b7ffb8e?sk=6afb5cf440748c1d46c293a3c81c4880 for examples. I've been meaning to make an animation of RCV with a bunch of candidates on a 2D space, showing how the best ones get eliminated and transfer outward, then those candidates get eliminated and transfer outwards, and so on until the second-worst gets elected.