@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
@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
@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. Thatâs 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-raisingâno 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 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.
@toby-pereira said in The dangers of analysis paralysis in voting reform:
Also for a score-based method, I'm still not convinced that STAR is the method. I said on the Election Methods list the other day that while basically all methods fail Independence of Irrelevant Alternatives (IIA), STAR seems to do so in a more wilful way. I'll just quote myself:
That's kind of interesting, because I took you as saying the opposite (which is also my understanding of STAR): that STAR doesn't have to fail IIA (or clone-independence), but intentionally chooses to do so because this leads to a slightly better outcome. With STAR, the optimal strategy is for every party to run 2 candidates, which gives every voter at least two choices they can feel comfortable with.
As an example, I'd much prefer a situation where both Biden and Kamala Harris were listed separately on the ballot so I could rank Harris higher (and help her win the runoff). Right now, I'm not happy with any of the candidates in the race; on a simple left-right scale I'm close to Biden, but I disapprove of him for reasons of competence. (But I'm sure as hell not supportive of any other candidate...) With STAR, every voter should have at least two choices they consider tolerable.
Personally, I think of STAR as just reversing the primary-then-general order: we have a general election to choose the best party (the score round), and then a "primary" where we pick the best nominee by majority vote.
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 advantageâit 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.
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 myselfâwon'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).
@masiarek said in "Problematic" Ballot Exhaustion examples - RCV IRV:
We need three small, illustrative elections to demonstrate each âproblematicâ box separately (avoid âLess Problematicâ 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"âno 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."
@sarawolk said in The dangers of analysis paralysis in voting reform:
@toby-pereira said in The dangers of analysis paralysis in voting reform:
Ranked Robin
We are planning to come back to the original intention around Ranked Robin, which is to stop branding Condorcet as a whole bunch of systems to fight between, and move to calling them one system, Ranked Robin, with a variety of "tie breaking protocols" a jurisdiction's special committee on niche election protocols could choose between. Honestly, specifying Copeland vs RP vs Minimax is way beyond the level of detail that should even be written into the election code or put to the voters.
Equal Vote's point with the Ranked Robin was never to say that Copeland is better than Ranked Pairs is better than Smith/Minimax. The point is that these are all equivalent in the vast, vast majority of scaled elections and that Condorcet as a whole is top shelf so it should be presented to voters as a better ranked ballot option. Ranked voting advocates should support it. The main reason Condorcet is not seriously considered is because of analysis paralysis and a total lack of interest in branding and marketing for simplicity and accessibility.
So then "Ranked Robin" is just supposed to refer to Condorcet methods in general?
I think that's a good strategy, but the presentation on the website made me think that Ranked Robin means Copeland//Borda specifically.
2 years later
I think Saari showed in his book that Cycle Cancellation//Condorcet is equivalent to Borda!
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.
@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?
@cfrank said in Cycle Cancellation//Condorcet:
Does this end up being different from ranked pairs? It has a kind of a co-âranked pairsâ 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 oftenâand by often I mean like 1% of elections :pâreturns 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 kâ>k+1.
This is different from Split-Cycle. Actually, I think it's equivalent to Minimax.
Method:
Behaves much like STAR, in that voters have less incentive to equal-rank several candidates (they want to make sure their favorite can beat the others). However, it maintains Favorite Betrayal.
Reason: Originally, I expected STAR's gimmick runoff not to have much of an effect on score's good behavior. But ever since @SaraWolk mentioned the possibility of candidates not having clones in the race, I keep finding more and more situations where STAR reacts catastrophically badly to party-coordinated strategy. This is really bad, because parties exist for the explicit purpose of coordinating strategy. I'll give more examples elsewhere.
@cfrank said in Cycle Cancellation//Condorcet:
Of all edges that belong to a cycle, identify those of minimum weight. Create a new tournament without those edges.
I think this step needs to be modified slightly to preserve those edges if they're part of another simple cycle where they're not the minimum-weight edge. In other words, we only eliminate an edge if it's the minimum-weight edge in every simple cycle it's a part of. If it's the minimum-weight edge in one cycle, but a very strong edge in another cycle, you don't want to eliminate it.