Best posts made by Lime

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.

Thank you so much for this post! It's great

@toby-pereira said in Optimal cardinal proportional representation:

There are several possible methods of converting an approval method to a score method, but the KP-transformation keeps the Pareto dominance relations between candidates and allows the methods to pass the multiplicative and additive versions of scale invariance, so my current thinking is that this is the optimal score conversion.

I'm not 100% sure about this myself—won't any transformation of the ballots discard some information? I'm not sure if applying the KP transform to range retains the core-approximation properties that make PAV so appealing (i.e. 2-approximation of the core, and satisfying core with enough similar candidates).

@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.)

@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.

q-Condorcet methods use quotas other than 50% to declare a Condorcet winner; for example, a 2/3-Condorcet method declares a candidate to be the winner if they defeat every other candidate by a margin of 2/3. By Nakamura's theorem, the q-Condorcet winner is guaranteed to be acyclic for all voter profiles if and only if q = (n_candidates - 1) / n_candidates. The same quota also guarantees that a q-Condorcet method is participation-consistent.

Working on this more. Right now I have some interesting questions, like: What if q depends on the number of ballots involved in cycles? Could some method satisfy Condorcet-like properties for a "mostly acyclic" electorate, but otherwise fall back on some other method? And do so in a way that still satisfies participation?

This seems like a nice way to smoothly interpolate between Condorcet and non-Condorcet methods (like score), depending on whether the optimality criteria for Condorcet are satisfied.

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.

@cfrank said in What does STAR Voting do when 2nd place is tied?:

If we were being engineers about choosing a high quality candidate to win the election, we could even compute the distribution of scores, take the candidates whose scores exceed some elbow point, and find the Condorcet winner among those candidates with the top scoring candidate as the backup if no Condorcet winner exists. That’s basically a generalization of STAR with a dynamic front-runner selection method.

What about a 50% cutoff? That would also dramatically reduce the incentive for turkey-raising—no point in pushing up a bad candidate to help them make the runoff, since now that doesn't eliminate another contender.

@toby-pereira said in Cycle Cancellation//Condorcet:

One thing you could do is look at every possible triple separately (similar to how Condorcet looks at pairs separately). So within each triple you remove cycles and get the pairwise comparisons for the candidates within that. Then you could do some sort of Ranked Pairs or Rivers process to "lock in" certain triples, but it's a case of deciding how to judge which are the ones to lock in first.

OK, having read more about split-cycle, I think I've come to the conclusion that simple cycles (i.e. a path that starts and ends at A, without repeating any points other than A) are more likely to work than triples. An explanations of split-cycle:
Consider a simple cycle. Affirm all defeats in this cycle other than the weakest. Repeat for all possible simple cycles.

So, it's a kind of local minimax.

So you can restrict yourself to a single simple cycle at a time, and maybe consider within this group who the local winners are?

@toby-pereira said in Entropy-Statistic-Weighted Approval Voting:

While I don't think it would be a good method in practice

The 2 most popular voting systems in practice are IRV and plurality. Anything is a good method in practice

@jack-waugh said in What Multiwinner Method To Push For Local Boards?:

Is monotonicity equally so important for the multiwinner context as it is in the single-winner context?

Yes—it makes no sense that, if I give a candidate an extra star, we respond by deciding the candidate is "too good to win" now. It also makes honest voting impossible (because ranking A over B is no longer the same as giving A more support, so you can't give A the correct level of support without knowing everyone else's exact ballot).

@cfrank said in Cycle Cancellation//Condorcet:

Does this end up being different from ranked pairs? It has a kind of a co-“ranked pairs” flavor.

Yes, it's slightly different. Very roughly (this isn't actually a correct characterization), you can think of it as being "all the places where Ranked Pairs, River, and Schulze agree" (all three methods return a winner selected by Split Cycle).

TBC, Split-Cycle isn't resolute (it often—and by often I mean like 1% of elections :p—returns multiple winners). So it's more of a way to winnow down the set of potential winners.

@cfrank said in Cycle Cancellation//Condorcet:

Identify the kth weakest edge. If it is part of a cycle, remove it. Otherwise, set k—>k+1.

This is different from Split-Cycle. Actually, I think it's equivalent to Minimax.