Before today, I thought one-sided strategy was impossible. It seems bizarre to imagine a situation where only one of the two parties is able to work out the correct solution.

Today I came across a video explaining how to vote strategically in Schulze. It said that, if you really want to make your vote count, you should put your favorite at the top; then, you should truncate your ballot below the candidates you think are unacceptable. This is great, right? Clean and concise explanation of a minimal defense.

Except I lied. The video was talking about IRV. This video—produced by a large, well-funded San Francisco advocacy group—was trying to "educate" everyone into using the exact opposite of the correct strategy for IRV!

This strategy is both highly ineffective and socially disastrous. It dramatically increases the risk of a center-squeeze. It would create even stronger polarization and more extremism than in our current system of FPP-with-primaries, where at least primary voters know to vote for electable candidates.

That's not to say strategy can't be done. Alaska Democrats pulled it off in the 2022 Senate race, where they managed to get everyone to rank Murkowski first. Except... Republicans didn't manage the same for Begich. That's a huge problem.

I don't know if the video I saw was stupidity or intentional disinformation. Either way, it shows a big problem with IRV and Condorcet-IRV hybrids: their complexity makes them very vulnerable to one-sided strategy. We can't expect both parties, or all voters, will be able to work out the best strategy and use it. It's completely possible that only one party will understand runoffs well enough to exploit them.

I don't think you can expect voters to consistently execute any strategy more complex than thresholding, in a way that cancels out across parties and candidates.

An unusual strength of cardinal methods is the strategy is so clearly, blatantly obvious that nobody is disadvantaged. In this sense, unlike IRV, score and approval seem remarkably resistant to one-sided strategy.

The labeling of +1/-1 is arbitrary. You could just as easily call them 0, .5, 1 instead.

Another is it gives write-ins an unfair advantage (they can win just by not being on the ballot, which keeps them from attracting too much attention).

It matters, but only a little bit.

If you're writing JS code on voting methods, you may want to talk to choco-pi on r/EndFPTP and his simulations.

@masiarek said in "Problematic" Ballot Exhaustion examples - RCV IRV:

We need three small, illustrative elections to demonstrate each ‘problematic’ box separately (avoid ‘Less Problematic’ Exhausted Ballots).

Really I'd just hammer IRV over and over again on participation failure. Exhausted ballots are a non-issue.

We need to find better names than "monotonicity" and "participation" that are easy to explain. Monotonicity is a complicated six-syllable word that, in everyday speech, literally means "boringness"—no wonder nobody cares. Rename it the basic @#$%ing sanity criterion.

Advertisement: a candidate is declared the winner and starts celebrating; then somebody comes up and explains they've found extra votes for the candidate, and the candidate suddenly loses. End with "Last year, Nick Begich lost the Alaska election because voting authorities thought he had too many votes. How could voting for someone make them lose? Don't let it happen here. Vote no on IRV."

@jack-waugh said in Approval Voting as a Workable Compromise:

Maybe our best marketing strategy is to try slide B2R IRV rating-ballots into the place of Hare IRV RCV in popular mindshare as a solution with the same flash but without the disappointing and counterintuitive results that Hare often delivers.

People have been trying this for as long as IRV has been proposed. The answer to "why does IRV keep gianing ground" is "because billionaires keep pouring money into FairVote and FairVote keeps lying about IRV".

There's nothing really wrong with approval, score, or STAR except that people heard about IRV first. As I've mentioned before, the easiest way to deal with that is to get a case to the Supreme Court that strikes down any nonmonotonic system as unconstitutional (a strategy that's already been used successfully in Germany).

@toby-pereira said in Easy-to-explain Proportional (Multiwinner) elections:

By the way, Satisfaction Approval Voting can only be described as semi-proportional. You're wasting part of your vote on candidates that aren't elected. It's like SNTV except that you can split your vote up. They both have similar problems to FPTP.
They might be easy to explain, but they're not worth explaining!

You're right, of course, but that's why I like to bring up SAV as an "obvious" system with an obvious flaw (spoilers). Then I explain how PAV/SPAV fix that flaw with a minor change--split a vote only after a candidate is elected, not before.

I'd just like to say this looks great and I'm very interested in seeing more! Quantile-normalization like this is very common in statistics. This has one especially nice advantage—it eliminates the "arbitrary number" criticism often made of score voting, which is that voters can assign arbitrary scales to their feelings of support/opposition for candidates that might not line up. Quantile normalization gives an equivalent, statistically well-defined scale for every voter.

2 years later

I think Saari showed in his book that Cycle Cancellation//Condorcet is equivalent to Borda!

@jack-waugh said in Approval Voting as a Workable Compromise:

I suggest that Approval makes it more work than necessary to vote responsibly as one has to resort to a stochastic technique.

Mixed strategies can be optimal in any electoral system.

@jack-waugh said in Approval Voting as a Workable Compromise:

I suggest that Score makes it more work than necessary to vote responsibly as one has to exaggerate support for ones compromise candidate.

…except, ironically, score makes randomization less important by letting you give partial scores instead of requiring you to vote at random.

@jack-waugh said in Approval Voting as a Workable Compromise:

Then there goes Score-B2R.

That's fine. STAR, Smith//Score, ranked pairs, etc. are all probably good enough. IRV isn't.

I've thought of a slightly-simpler variant on MARS: Each candidate's score is equal to their range score, plus the score of the strongest (highest-scored) candidate they majority-beat. Thinking through what properties this would have.

@gregw said in ABC voting and BTR-Score are the single best methods by VSE I've ever seen.:

Are you uncomfortable with BTR-Score? As a Condorcet method, it should be safer than most new systems. It would elect the “beats all” winner if there is one. Otherwise, it would elect someone from the Smith set.

The problem is with strategic voters. Lots of Smith-efficient methods do really badly when voters are strategic, unfortunately, including the ones I listed (Ranked Pairs & such).

@toby-pereira said in ABC voting and BTR-Score are the single best methods by VSE I've ever seen.:

What we really need (and which is unattainable right now for most methods) is to see what would happen in real life elections with real voters. Not under the assumption that a particular simplistic strategy model gives good results, and not even that the game theoretically optimal strategy leads to good results, but that real life voter behaviour would lead to good results.

Technically yes, but I'd feel very uncomfortable with any method where the game-theoretically optimal strategy leads to bad results, even if experiments showed the method doing well. I'd be worried voters just haven't figured out the correct strategy yet, and as soon as someone explains it to them all hell will break loose.

This is how Italy's parliament got so screwed up. They had a theoretically proportional mechanism that can be broken. It looked fine at first—because it took Berlusconi 2 or 3 election cycles to recognize the loophole and exploit the hell out of it.

So, in other words, you need an actual proof, not just "well, when I tried a couple strategies..." Otherwise, you'll find out 5-10 years later that there's some edge case where your method is a complete disaster, and after the whole IRV fiasco, electoral reform will end up completely and thoroughly discredited. (Italy went back to a mixed FPP-proportional system after the screwup.)

@ex-dente-leonem said in ABC voting and BTR-Score are the single best methods by VSE I've ever seen.:

@lime said:

The CPE paper shows very strong results for Ranked Pairs under strategic voting. This is well-known to be wildly incorrect: the optimal strategy for any case with 3 major candidates is a mixed/randomized burial strategy that ends up producing the same result as Borda, i.e. the winner is completely random and even minor (universally-despised) candidates have a high probability of winning.

I don't believe Ranked Pairs is analyzed in the STAR paper, unless you're thinking of Jameson Quinn's original VSE document or a different paper.

I think the important takeaway here is less about trying to game out every strategy possible than the fact of how these models perform under the same conditions as what the authors believe to be their best modeled simulations, given that such simulations are an integral part of EVC's and others' advocacy efforts. (For quite necessary reasons, as we have no historical results for many methods, and as noted such historical samples would likely be unacceptably small or fail to capture the development of strategy over time.) I'd definitely welcome further testing in other simulations with mixed strategies and other voter models as realistic as we can make them.

I believe the above should be taken as impetus for theoretical analysis of why these methods seem to perform so well, and the key may be that they're all hybrid methods involving pairwise comparisons and sequential eliminations for all candidates at some point, which reasonably makes potential strategies that much harder to coordinate.

I'm talking about the original VSE document, yes. And my point is that I think the strategic voting assumptions are wholly unrealistic to the point that they will probably miss the vast majority of pathologies, like it does for Ranked Pairs and Schulze.

Thanks for these simulations, they're definitely interesting @Ex-dente-leonem

That said, I think we might be making the mistake of getting sucked deeper and deeper into a drunkard's search. The simulation results here don't really say much, except that we haven't figured out a strategy that breaks Smith//Score or ABC voting yet. That's not surprising, given we only tested 5 of them.

The difficult part of modeling voters isn't showing that one strategy or another doesn't lead to bad results. It's showing that the best possible strategy leads to good results. There's nothing wrong with testing out some strategies like in these simulations, but these are all preliminary findings and can only rule voting methods out, not in.

Just because every integer between 1 and 340 satisfies your conjecture, doesn't mean your conjecture is true. You still need to prove your conjecture.

This isn't just hypothetical. The CPE paper shows very strong results for Ranked Pairs under strategic voting. This is well-known to be wildly incorrect: the optimal strategy for any case with 3 major candidates is a mixed/randomized burial strategy that ends up producing the same result as Borda, i.e. the winner is completely random and even minor (universally-despised) candidates have a high probability of winning.

The methodology here completely fails to pick up on this, because it only tests pure strategies (i.e. no randomness and everyone plays the same strategy). In practice, pure strategies are rarely, if ever, the best. Ignoring mixed strategies has led the whole field of political science on a 15-year wild goose-chicken-chase that would've been avoided if anyone had taken Game Theory 101.

The issue is that defining VSE for the multi-winner case is, uhh, complicated. In particular, PR doesn't do a good job of satisfying VSE under the most intuitive model, one where voters' utilities are additive, i.e. satisfaction equals the sum of scores you assign to each candidate. If that was actually the case, the best methods would be winner-take-all (pick the candidates with the highest scores).

The ideal situation would be to have voters score each set of candidates, e.g. "a committee with A, B, C has a score of 3; one with A, B, D has a score of 5, ...". Then we could maximize the sum of scores. However, that's completely impractical for voters, it's difficult to model utilities, and a method like this would be extremely vulnerable to strategic exaggeration.

So, in the proportional context, so far we've found it easier to just deal with pass/fail criteria rather than VSE. That's not to say VSE couldn't be extended to the multiwinner context, it's just that it's complicated and we don't know how yet.

@jack-waugh said in A simple improvement of Maximin:

How would candidates who are in partial agreement about issues that are important to them (such as bombing other countries or not) but in disagreement on other issues (e. g. cutting up children) decide whether to ally?

Dunno, that's up to them. In my own proposal, it would be if two candidates want an enforced guarantee of later-no-harm so they don't end up locked into a Burr dilemma.

(That said, I'm becoming increasingly convinced that the Burr dilemma isn't real, and it's caused by unrealistic modeling or a poor understanding of game theory.)

I already gave my response to this in DMs with you, so I'll copy-paste it here:

I like the rule well enough, and it seems good! I’m a bit more interested in whether we can use party identification to solve the Burr dilemma, and score's problem with ensuring zero-information honesty.

Say we made it so that, in the first step, we used score voting: each alliance's score is the score of its best-performing candidate, and we eliminate any candidates with score less than or equal to the second-best alliance's score. Then, in the second round, we use some method like MMPO or quadratic voting that encourages honest rankings in zero-information elections.

The goal being to get semi-honest rankings of parties, combined with fully-honest rankings of candidates. Voters will probably know a lot about the viability of different alliances, so those votes can't be guaranteed to be honest. But candidates within each alliance are likely to be closely-matched, so in that case, voters are encouraged to give a sincere ordering.

This method is effectively STAR+; it's like STAR, but the runoff includes all similarly-popular candidates of the same party.

@cfrank said in What type of party system are STAR and approval voting likely to promote, are there papers on this?:

I don’t think there are any good empirical and longitudinal case studies on emergent behaviors in government like party formation or coalitions as a consequence of either voting method. Approval voting and STAR aren’t used in many national elections as far as I am aware. Studies that suggest any patterns of emergent behaviors of that type related to approval voting or STAR voting would likely be simulations via agent-based modeling.

So far, no modern country has used a system other than plurality or plurality-with-runoff to elect its head of state/government. (Although Venice did use approval voting for most of its history.) So, sadly, there's not much—if any—empirical research.

@gregw said in score interval: score with additional protection against the chicken dilemma:

Unfortunately I do not understand this. A simple as possible explanation might help.

As in, eliminate any candidate with an average rating below 50% of the maximum.