As the author, I think this has generally stood the test of time pretty well. There are various changes I'd make if I were doing a rewrite today; but overall, these are minor.

Aside from those generally-minor changes, I think that the key message of this piece remains important to the purpose of Less Wrong. That is to say: making collective decisions, or (equivalently) statements about collective values, is a tough problem; it's important for rationalists; and studying existing theory on this topic is useful.

Here are the specific changes I'd make if I were going to rewrite this today:

• The most significant change is that I'd probably start off with multi-winner voting theory, because I've come to believe that it is clearly more important than single-winner theory overall.
• I would avoid quick-decaying cultural references such as the "American Chopper" meme. There are also a few passages where the language is noticeably awkward and could be rewritten for clarity.
• Unlike my attitude in this piece, I've come to accept, although not to like, the "Rank Choice Voting" terminology.
• I am no longer on the board of the CES; my term ended. I still endorse their work, though I wish they'd do more on multi-winner reform rather than focusing so strongly on single-winner methods.
• Today, I wouldn't be quite so dismissive of the issues with asset voting. Though minor and probably resolvable in practice, they are actually quite thorny from a philosophical point of view.
• On the topic of comparing multi-winner methods, and which ones are best, I have substantially more that I could say today. In fact, I plan to write this new material up as a new article in this series. In the context of this article, though, I wouldn't fully explain that new material, but rather just briefly outline it. Essentially: I have developed a metric for comparing outcomes of different voting methods. This metric is not directly utilitarian, but I have arguments that suggest it is among the "best known strategy-robust estimators of the difference from the optimal utilitarian outcome".
• The hashtag "#ProRep" seems to have won over "#PropRep" as a way of tagging the topic of proportional representation.
• I did not in fact finish the "playable exploration" that I talked about in the penultimate paragraph. But I did, just three days ago, finish my doctorate (defend my thesis) in statistics, so I may end up having time to finally make that playable exploration soon. Certainly, if I can get funded with at least $45K for around 6 months of work, I will finish that and other productive voting theory work that I think would be well worth the money.

I think this post should be included in the best posts of 2018 collection. It does an excellent job of balancing several desirable qualities: it is very well written, being both clear and entertaining; it is informative and thorough; it is in the style of argument which is preferred on LessWrong, by which I mean makes use of both theory and intuition in the explanation.

This post adds to the greater conversation by displaying rationality of the kind we are pursuing directed at a big societal problem. A specific example of what I mean that distinguishes this post from an overview that any motivated poster might write is the inclusion of Warren Smith's results; Smith is a mathematician from an unrelated field who has no published work on the subject. But he had work anyway, and it was good work which the author himself expanded on, and now we get to benefit from it through this post. This puts me very much in mind of the fact that this community was primarily founded by an autodidact who was deeply influenced by a physicist writing about probability theory.

A word on one of our sacred taboos: in the beginning it was written that Politics is the Mindkiller, and so it was for years and years. I expect this is our most consistently and universally enforced taboo. Yet here we have a high-quality and very well received post about politics, and of the ~70 comments only one appears to have been mindkilled. This post has great value on the strength of being an example of how to address troubling territory successfully. I expect most readers didn't even consider that this was political territory.

Even though it is a theory primer, it manages to be practical and actionable. Observe how the very method of scoring posts for the review, quadratic voting, is one that is discussed in the post. Practical implications for the management of the community weigh heavily in my consideration of what should be considered important conversation within the community.

Carrying on from that point into its inverse, I note that this post introduced the topic to the community (though there are scattered older references to some of the things it contains in comments). Further, as far as I can tell the author wasn't a longtime community member before this post and the sequence that followed it. The reason this matters is that LessWrong can now attract and give traction to experts in fields outside of its original core areas of interest. This is not a signal of the quality of the post so much as the post being a signal about LessWrong, so there is a definite sense in which this weighs against its inclusion: the post showed up fully formed rather than being the output of our intellectual pipeline.

I would have liked to see (probably against the preferences of most of the community and certainly against the signals the author would have received as a lurker) the areas where advocacy is happening as a specific section. I found them anyway, because they were contained in the disclosures and threaded through the discussion, and clicking the links, but I suspect that many readers would have missed them. This is especially true for readers less politically interested than I, which most of them. The obvious reason is for interested people to be able to find it more easily, which matters a lot to problems like this one. The meta-reason is that posts that tread dangerous ground might benefit from directing people somewhere else for advocacy specifically, kind of like a communication-pressure release valve. It speaks to the quality of the post this wasn't even an issue here, but for future posts on similar topics in a growing LessWrong I expect it to be.

Lastly I want to observe the follow-up posts in the sequence are also good, suggesting that this post was fertile ground for more discussion. In terms of additional follow-up: I would like to see this theory deployed at the level of intuition building, in a way similar to how we use markets, Prisoner's Dilemmas, and more recently considered Stag Hunts. I feel like it would be a good, human-achievable counterweight to things like utility functions and value handshakes in our conversation, and make our discussions more actionable thereby.

I haven't mentioned futarchy ("markets for predictions, votes for values") at all here. Futarchy, of course, would not be classed as a voting method in my typology; it's something bigger than even than my concept of a voting system. I think that the main useful thing I can say about futarch is: if you're going to spend energy on it, you should spend some energy on understanding lower-level voting methods too.

ETA: I guess I think I can expand on that a bit. The issue is that when you embed one system inside another one, there's some inevitable bleed-over in terms of incentives. For this meta-reason, as well as for the simple reason of direct applicability, one lesson from voting theory that I think would apply to futarchy is that "patching a problem can make it worse, because strategic outcomes can be the 'opposite' of unstrategic ones." That's an intuition that for me was hard-won, and I wouldn't expect it to be easy for you to learn it just by hearing it. If that's true and you still want to learn it, spend some time thinking about honest and strategic outcomes in various voting methods in the five levels of pathology I mentioned above. The playable exploration I mention at the end will substantially focus on these ideas, in a way I hope will be visually and interactively easy to digest.

Most elections aren't big. Most elections are about questions like a random group electing their chairman. It's a lot easier to convince a random group to use a different voting system than to change the way voting is done on a national election.

I think the most likely way to create change in the national way of voting is to first change the way smaller groups run their elections.

Your post doesn't really analyses the desirable features of an electoral system and I think that's a common failure mode for people who think theoretically about voting systems without any practical involvement into implementing them.

Running elections costs time and given that most groups need to elect their chairman every year minimizing the amount of time it takes to make that election is desirable.

The role of an election is not just about finding the optimal candidate but about establishing that the candidate was picked in a trustworthy way. This means that "our tech person runs a server and we trust the results of the voting software" is not a satisfactory strategy. Complex counting rules also make fraud easier.

Exciting stuff! It would not shock me in the least for this to be a common point-of-reference for various rationalist experiments (i.e. houses, startups, etc). I have a bunch of questions:

1) Do these voting systems have anything to say about voting for referendums, or is the literature constrained to candidates? Is there any sense in which a batch of competing referendums would not be treated the same as single-winner races?

2) You mention the practical concerns of laypeople being able to grasp the process and counting the votes a few times - is there a body of research that focuses on these elements, or is this work being done by the Center for Election Science?

3) You mention the use of a Condorcet method being used by Debian in internal voting - is there a sense of which methods are suitable for use in organizational voting, as distinct from political voting, ie some of them are unusually sensitive to scale? Further, how is deployment in an organization weighed as evidence regarding deployment in elections?

4) Can you recommend a source which discusses voting theory from the perspective of information aggregation, in the same way as has been done for markets?

I might’ve missed this, as I didn’t read some of the sections of this post quite as closely as I could have, but here’s a question which, I think, is critical:

Has there been any research aimed at determining which voting method is easiest to understand (for people who aren’t specialists in the field[1], or, in other words, for the general public)? (And, by extension: how hard is each method to understand? How do they compare, in this regard?)

Comprehensibility by the general public seems to me to be a sine qua non of any voting method we’re to consider for adoption into the political process.

[1] Or, as we might say, “voting theory nerds”.

I've been moderately hard on IRV, and its supporters, in the above. I want to state here for the record that though IRV is my least-favorite serious* reform proposal, I think that it would solve a substantial fraction of the voting-system dysfunction of FPTP; that if IRV were more of a focus of this essay than it is, there are other decent pro-IRV arguments I could include; and that there are IRV supporters whose intellect and judgement I respect even as I disagree with them on this.

*That excludes Borda. #SorryNotSaari

I've curated this post for these reasons:

• This is an opinionated introduction to a piece of math-based social theory.
• The two followups on Moloch [LW · GW] and Alignment [LW · GW] also helped flesh out the key intuitions.
• It's written by someone with a lot of expertise in the field.

My biggest hesitation(s) with curating this:

• I didn't find it practical (yet). In my head voting theory is still its own disconnected thing from the ways I think about solving social or utilitarian problems in my life.
• It's quite long.

Overall though the opinionated style of the writing made it much more readable, and I expect to come back here when thinking more about preference aggregation in my own work (on LW). I'm a big fan of people writing down their expertise in a digestible way - thanks for writing these up!

I'm quite interested in voting systems, but I was surprised to discover that the general consensus is that score beats approval! I checked it out and it seems to be a robust finding that in real life people understand & are happier with score, but this surprised me. 

I'd think that since there are so many options for score, it'd be a bit overwhelming and hard to figure out how to optimize.  Whereas with approval it's basically "vote for the minor candidates you like better than the major ones; and also vote for your least unfavorite major candidate." Which is simple enough.

I can more clearly see the argument for three to five scoring options instead of approval. If you're, say, a Warren supporter in the 2020 election (which of course is now a free-for-all approval voting bonanza) do you vote for Biden or not? If you don't vote for him, you risk throwing the election to Trump; whereas if you do, you may end up giving the election to Biden over Warren. So a middle-ground-y thing seems reasonable here. (A counterargument here is that with polling, it can be more clearly seen whether a mass effort by the Democratic Party Establishment to get liberals in line is necessary, or whether people can coalesce behind Warren or Sanders or whoever.)

Three options nicely correlates with "like, neutral, dislike" and five nicely with "love, like, neutral, dislike, hate" as heuristics for honest voting. I'm just apprehensive about a hundred. I don't even know how I'd vote with more than three candidates to rate on such a high scale, I shudder to think how a low-information voter would do it.

There are two things I would add to this:

1. The other big disadvantage of Borda is teaming, where nominating more candidates makes a party more likely to win (opposite of vote-splitting).

2. It seems that to me the advantage of party-less systems in multi-winner elections is that, if your voting system succeeds so well that parties are no longer playing such a big role, you don't have to later change it to be party-less to complete the transition. :)

...also I was going to ask a question about rated-runoff methods (i.e., did anyone consider the most obvious form of rated runoff) but in fact you answered it on your VSE page where you explain score-runoff voting. So, thanks for introducing me to that!

Edit: One addiitional note -- it seems to me that the endorsement mechanism you came up with for 3-2-1 voting, where rather than specifying a full ballot of your own you can just cast a single vote for a candidate and thereby copy their ballot -- that's something that could be tacked on to a lot of methods, couldn't it? As a way of simplifying them for people who really can't handle the additional complexity. (Not that still really licenses that much additional complexity, but...) I guess it does have the potential downside that outside the context of something like 3-2-1 voting, where it can be done implicitly rather than explicitly, it might lead people to just short-circuit the process and subvert the point of the new voting system...

Thanks for writing this! Very informative.

I saw a paper (which I don't remember enough about to find, unfortunately) in which a bunch of voting theorists got together and voted on the best voting method, using approval voting (I think?), and the winner was approval voting. I wonder if anyone also saw this and saved it so they can tell me how to find it?

There's another way that Arrow's theorem was an important foundation, particularly for rationalists. He was explicitly thinking about voting methods not just as real-world ways of electing politicians, but as theoretical possibilities for reconciling values. In this more philosophical sense, Arrow's theorem says something depressing about morality: if morality is to be based on (potentially revealed) preferences rather than interpersonal comparison of (subjective) utilities, it cannot simply be a democratic matter; "the greatest good for the greatest number" doesn't work without inherently-subjective comparisons of goodness. Amartya Sen continued exploring the philosophical implications of voting theory, showing that the idea of "private autonomy" is incompatible with Pareto efficiency.

I haven't really been able to understand this from a philosophical perspective.

Representation theorems like VNM, Savage, Jeffrey-Bolker, etc say that the preference view is equivalent to the subjective utility view.

Harsanyi says that utility maximization and Pareto-efficiency are interchangeable concepts.

Yet, you say that if morality is to be based on preferences, rather than utilities, we cannot define "the greatest good for the greatest number".

How can this be, if the views are equivalent?

I'm curious about the question of wasted votes. In the link you provide to explain PLACE, it talks about wasted votes a lot. My understanding is this:

1) Under the loose definition, any vote not for the winning candidate is wasted.

2) Under the strict definition, any vote not needed to win is also wasted.

This is deeply unintuitive to me. Just inferring from the above, this suggests that what should be done is to calculate the least-worst smallest-majority candidate, and then everyone else stays home. The direct implication is that votes are intrinsically worthless, which seems weird. As a term-of-art it seems to be so heavily dependent on FPTP as to be inapplicable elsewhere.

Am I reading too much into it, and it just basically means 'the badness of FPTP'? How prevalent is this concept in distinguishing between voting systems, in your view?

Has it undergone any recent changes, for example as a result of the voting utility calculations when comparing different decision theory agents?

What are the improved Condorcet methods you're thinking of? I do recall seeing that Ranked Pairs and Schulze have very favorable strategy-backfire to strategy-works ratios in simulations, but I don't know what you're thinking of for sure. If those are it, then if you approach it right, Schulze isn't that hard to work through and demonstrate an election result (wikipedia now has an example).

Should this be broken up into sub-posts?

I nominate this post because it does a good job of succinctly describing different ways to approach one of the core problems of civilization, which is to say choosing policy (or choosing policy choosers). A lot of our activity here is about avoiding catastrophe somehow; we have spent comparatively little time on big-picture things that are incremental improvements.

Anecdotally, this post did a good job of jogging loose a funk I was in regarding the process of politics. Politics is a notoriously *ugh field* kind of endeavor in the broader culture, and a particular taboo in this community. And yet, the very act of seriously considering what the options are is a soothing balm when you are otherwise in a state of overwhelming disgust. It’s like the ritual of evitable dismay.

Not the best place to put this comment, but there's a confusing mistake on the PLACE FAQ where the pie candidate shows a voting option for "Other Ice Cream Candidate" instead of "Other Pie Candidate."

Does anyone have an electorama account to remedy that?

Due to its complexity, [SODA] is probably not a practical proposal, though.

I don't follow, how is that complexity a problem? I googled SODA, stumbled onto a sample ballot here: https://wiki.electorama.com/wiki/SODA_voting_(Simple_Optionally-Delegated_Approval)#Sample_Ballot it doesn't seem like it even matters if voters fully understand the (very succinct) instructions, the thickest voters will just treat it like an approval voting system, which is pretty adequate, isn't it?

Having the candidates' delegations be in there wont really impose much cognitive overhead, humans are very sensitive to the alignments of their leaders/factions, that information is largely already in their heads and taken into account.

Have I not understood what you were referring to? Is the voter interface not where it is?

Many of these methods can (I think) select multiple winners. For large elections, this is usually pretty unlikely, but still possible. What's your preferred method of dealing with that possibility? And have you looked into maximal lotteries? http://dss.in.tum.de/files/brandt-research/fishburn_slides.pdf

(I had several hundred karma on the old Less Wrong site under a nym. Is there both a reason to want to reclaim that and a way to do so?)

It seems like a lot of the challenges in designing a voting system stem from wanting to give each geographic region "their" representative, while not letting people "throw away" their vote.

If we abandon the first part (which is totally reasonable here in the 21st century, with the takeover of digital communication and virtual communities), there is a clean solution to the second part.

Specifically, remove all the names from the ballot, and have people only vote for their preferred party, then allow each party that gets more than [small]% of the vote to designate a representative, who has voting power equal to the number of votes they got (or round it off in some way, to improve legibility and avoid recount recriminations). Those 10-20 unequal voters then meet, discuss, compromise, vote, etc. on the actual legislative proposals (as representatives of their parties, so everything would also get vetted by the party elites in some way). Thus, each individual can find or found the party that most closely matches their own values, and their vote is never "wasted" because at worst their minor party just votes with the closest major party, but that decision gets made by informed political actors, who know their relative voting power and the true positions of the other parties, not masses of deliberately-lied-to people who don't know if there are enough [new party] members to unseat [existing party].

Kenneth Arrow, proved that the problem that Condorcet (and Llull) had seen was in fact a fundamental issue with any ranked voting method. He posed 3 basic "fairness criteria" and showed that no ranked method can meet all of them:

Ranked unanimity, Independence of irrelevant alternatives, Non-dictatorial

I've been reading up on voting theory recently and Arrow's result - that the only voting system which produces a definite transitive preference ranking, that will pick the unanimous answer if one exists, and doesn't change depending on irrelevant alternatives - is 'one man, one vote'.

“Ankh-Morpork had dallied with many forms of government and had ended up with that form of democracy known as One Man, One Vote. The Patrician was the Man; he had the Vote.”

In my opinion, aside from the utilitarian perspective offered by VSE, the key to evaluating voting methods is an understanding of strategic voting; this is what I'd call the "mechanism design" perspective. I'd say that there are 5 common "anti-patterns" that voting methods can fall into; either where voting strategy can lead to pathological results, or vice versa.

One recent extension to these statistical approaches is to use RL agents in iterated voting and examine their convergence behaviour. The idea is that we embrace the inevitable impossibility results (such as Arrow and GS theorems) and consider agents' ability to vote strategically as an opportunity to reach stable outcomes. This paper uses very simple Q-learning agents with a few different policies - epsilon-greedy, greedy and upper confidence bound, in an iterated voting game, and gets behaviour that seems sensible. Many thousands of rounds of iterated voting isn't practical for real-world elections, but for preference elicitation in other contexts (such as value learning) it might be useful [LW(p) · GW(p)] as a way to try and estimate people's underlying utilities as accurately as possible.

I would weakly support this post's inclusion in the Best-of-2018 Review. It's a solid exposition of an important topic, though not a topic that is core to this community.

I think voting theory is pretty useful, and this is the best introduction I know of. I've linked it to a bunch of people in the last two years who were interested in getting a basic overview over voting theory, and it seemed to broadly be well-received. 

his last name is last name is great source of puns

Typo: his last name is a great source of puns.

The greater the number of voters the less time it makes sense as an individual to spend researching the options. It seems a good first step would be to randomly reduce the number of voters to an amount that would maximize the overall quality of the decision. Any thoughts on this?

It seems that to lift up one candidate to the top of our ballots we are implicitly expressing a judgement that they're better than every other candidate in the contest. Problem is, most of us know nothing about most of the candidates in most contests. We shouldn't be expressing things like "A > B > all others". We should prefer to say "A > B" and leave leave every other comparison grey. Let other voters, who actually know about C and D and E fill in the rest of the picture. There might be candidates who are better than A. We shouldn't pretend to know.

So my question is.. do you know of any systems that incent or at least allow voters to express their uncertainties?

I'm seeing Dark Horses everywhere, when I think about specific ways of implementing that.

[I'm having some thoughts about collaborative filters/content ranking/recommender systems. I'm not sure how relevant they are to voting theory in elections, related, I suppose, so I wont omit them.

Imagine a gang of <bad people who do not represent the demographic of the site> going to every old thread that not many people are paying attention to, posting a comment espousing <bad> views, then casting, say, 10 Comparison Judgements saying "our <bad> comment is better than the incumbent top comment". When you break up the task of ranking the whole set, so that we can each focus on comparing the candidates we know, leaving the rest to others, non-representative sections of the population will dominate some sections of the job, malicious or not. When they can create any number of new sectors at will, at the top of the ranking, in ways people are unlikely to notice quickly enough to fix, that will create many problems. I suppose... the solution to monitor the way the full ranking is being broken up, in some way, and look for skewed samples?

This might be easier to tackle in collaborative filtering if the system had some general way of noticing that the <bad> users are generally, reliably very different from <normal> users, that <bad> users and <normal> users don't generally like the same things, and that the preferences of <bad> users shouldn't be considered in forming content rankings for normal users. I think a lot could be done with that. I know that sounds like it would thicken our tribal filter bubbles a whole lot, but once we can name and characterise the people of each filter bubble it becomes a lot easier to figure out how to bring them back together. They were already apart, you see. Identifying them doesn't make it worse. Once you can identify them, detecting shared ground between hostile tribes becomes trivial. Being able to identify judgements that even very different sorts of people agree on could be generally useful as a heuristic for finding objective truths. I don't know what would happen if you told the system to strongly amplify anything that fits into those hot intersections. It's not inconceivable to me that it'd give rise to some unprecedented sort of harmony.]

Re SODA: The setup appears to actively encourage candidates to commit to a preference order. Naively, I would prefer a modification along the following lines; could you comment?

(1) Candidates may make promises about their preference order among other candidates; but this is not enforced (just like ordinary pre-election promises). (2) The elimination phase runs over several weeks. In this time, candidates may choose to drop out and redistribute their delegated votes. But mainly, the expected drop-outs will negotiate with expected survivors, in order to get at least some of their policies implemented (with the same kind of enforcement as regular pre-election promises). Hence, this phase is "coalition building".

An interesting final phase (3), in order to encourage compromise / beneficial trade would be something like: Once we are down to candidates with > 25% approval, we randomize the result. The probability of a candidate to win could be something like the square, or third power, of his approval. The threshold of 25% is in order to prevent complete crackpots from winning the election, and might need to be even more brutal. The randomization serves to allow the two remaining highest approval platforms to negotiate a compromise, weighted by their chance of winning the final lottery. In practice, one would hope that the randomization is never applied: That is, the highest candidate makes enough concessions in order to make the second candidate agree to drop out.

This way, we preserve minority rights, and get a pretty good outcome if the candidates are actually reasonable and trustworthy parties (instead of persons) that are capable of committing to modify the values they will espouse once in power.

Obvious disadvantages are (1) negotiation skill and integrity become essential (integrity in the christiano sense: You need to be predictable in which promises you will break under which contingencies), because the winner is decided though coalition building, rather than voting; and (2) some voters might object to shady backroom deals being the explicit procedure, and (3) randomization may make losers very pissed if the dice are ever rolled (which hopefully is never, because of positive-sum trades).

You can obviously combine this with a 3-2-1 system (where only candidates reaching at least 50% "OK" votes are eligible, and otherwise "Good" votes are counted; if no candidate receives 50% OK, then the election is repeated, under the assumption that Belgium is better than Trump, i.e. better a constitutional crisis and government by interim civil servants than government by crazy elected officials).

edit: I forgot to mention the other big advantage of the probabilistic phase (3): Enforcing continuity, i.e. preventing small factions from gaining oversized influence by playing kingmaker.

Thanks for this introduction to voting systems! I always wanted to know more about them, but never actually got to study it more - so usually I just suggested approval voting as a reasonable default. (Hence we use it in CZEA)

Btw what do you think of this voting method? https://web.d21.me/en/ (pushed by somewhat eccentric mathematician-trader-billionaire Janecek)

(Btw I would suggest this post gets to curated)

Dear Jameson, as you say the theme is extremely important, but I miss more about Storable Votes: one period Arrovian results deeply change in dynamic voting scenarios. I have recently written two articles about this: one has been published in Journal of Economic Interaction and Coordination, the other is still a pre-print:

https://www.lesswrong.com/posts/5wqFoHBBgpdHeCLS6/storable-votes-with-a-pay-as-you-win-mechanism-a [LW · GW]

I also suggest you to read the Casella and Mace review about “vote trading” (there a is Journal version, here you have the pre-print):

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3680422

Hi Jameson, brilliant post. I have some questions regarding the candidates in an election : 

1. What are the implicit and explicit assumptions we make about candidates? 
2. Would it be possible to incentivize preferable behavior from voters by making the candidates play an anonymous game prior to the election? For example lets say we have 100 candidates that we want to narrow to 10.  If we, for example, made the 100 candidates answer 5 pertinent questions in a digital form and had 1000 voters rank order(or other voting function of choice) the responses of 10 random candidates, we could take the top 10 performing candidates and then have a non-anonymous round of voting. 

Just found this and I have question and comment.

Q. Here (NZ), local body elections are usually STV for both mayor and councillors. It was seen as a way to get around vote-splitting leading to an unfavoured winner largely. There is always idle tea-time discussions about strategic voting without anyone getting sufficient interested to really analyse it. Your comment about it strategic voting in preference system revived my curiousity. How do you game an STV system? The best we could manage is that it seem best to rank all the candidates, rather than just ranking the ones you want to win.

And comment on how to get away from FPTP. NZ moved to MMP in mid 90s. It happened via two referenda. The first was simple question about retain FPTP or change system, and a second question asking for preference among various proportial systems. There was overwhelming support for change and MMP won the preference. A second referendum was stark choice between MMP (with all the parameters defined) and FPTP. 

Doing the move this way, allowed for a vote for change away from FPTP BEFORE having to make decision on what to change to, with option of changing your mind at second referendum if you hated the proposed replacement. Those fighting for reform are not splitting their vote around different systems until a decision to ditch FPTP is made. It should be said that public had appetite for change but neither major party did. 

I think MMP won the proportional preference because people wanted local representation. I believe the change achieved it's goal but strategic voting in almost the norm and we occasionally have the tail wagging the dog (which usually results in electoral punishment for offender but some parties are slow learners - well one in particular). With no upper house and only the Queen's representative with reserve powers, MMP has worked a brake on parlimentary power.

"Because LNH is incompatible with FBC, it is impossible to completely avoid the chicken dilemma without creating a center squeeze vulnerability, but systems like STAR voting or 3-2-1 minimize it."

Unfortunately, the main weakness of STAR voting is in the automatic runoff system it introduces. Automatic runoff systems (of which IRV is the most known) sacrifice numerous benefits and exhibit various pathologies in the name of speed. STAR voting, while far better than current plurality systems, is unfortunately still introducing an unnecessarily layer of complication for highly questionable benefit. A manual second round vote, while slower and more complex, would produce a better overall result, and a simple Score Vote is faster and simpler, while performing as well or outperforming STAR in the sense that it has comparable voter satisfaction without conceptually introducing pathologies caused by the presence of an automatic runoff.

https://www.rangevoting.org/BurrSummary.html

https://rangevoting.org/StarVoting.html

Hey

Could you dive into the strategic approach challenges you see with quadratic voting a bit further? The way I see it, a decentralised blockchain which rewards consensus can ensure honesty using simple game-theoretic principles. Quadratic voting is especially useful in reputation scoring, where both the magnitude and the diversity of the votes are important to ensure robustness.

More specifically, I'm referring to the quadratic voting method proposed in the Capital Restricted Liberal Radicalism paper. I'm assuming you're referring to the same thing, however I'll state it for clarity:

Vote received = Sq.(Sq.Rt. Vote1 + sq.rt. vote2 ... + sq.rt. voteN)

An example would be where people earn non-transferable "RP" which can be "staked" on other individuals, following which they earn or lose rep based on the sq.(sum(delta change)) of all individuals staked. Similarly, the person in favour of whom these stakes are made, increases his RP by applying the quadratic vote formula above on all stakes received.

Assuming RP is tied to a tangible incentive (like better interest rates), such a system should incentivise picking trustworthy people, and picking as many of them as possible; since picking trustworthy people is the most likely way to achieve consensus, cause a positive delta change, and thus gain RP.

Is there some major mode of failure I'm missing? Do you see quadratic voting of this kind becoming more important as we create consensus mechanisms that can increase the likelihood of honesty?

This post introduced me to a whole new way of thinking about institutional/agency design. The most merit, for me, was pointing out this field existed. The subject is close to one of the core subjects of my thoughts, which is how to design institutions that align selfish behavior with altruistic outcomes on different hierarchical levels, from the international, to the cultural, national, communal, relational, and as far down as the subagent level.

Hello,

Thank you for that very insightful article.

Sorry to post a question so long after its publication, I hope it will reach you. I'm wondering how all these methods stands for anonimity of voters, I'm explaining: in most election, there is a lot of candidats (at leat, it's the case in France, where for example the last 1st round of Presidential election had 11 voters. That leads to a lot of unique permutation (for example, with Approval, we can encode 2^11 = 2048 states, for a fully sorted algo we get 11!, etc). In France, votes are organized in small polling station of generally less than 2000 people.

So it seems that a bad actor would be able to threat people to vote for someone, forcing them to vote for a special encoding, and that just by comparing the number of total vote for that encoding, the bad actor would get a good guess about the actual vote of the threaten people.

Is there any electoral algorithms robust againts that threat vector?

Thanks,

Another view of voting is where an objective opinion or belief is being formed about ANYTHING that can be named. It might be a belief about utility where the utility can only be seen subjectively but an objective value would be useful in planning, for instance. Another example is determination of what a given set of users might buy given prior page views, or what the value of a given piece of intelligence is to a given audience at a given time and related to a given topic. Such a voting structure is needed in crowd sourcing and in 'training'/'supervision' in machine learning. It is also necessary for determination of what is or is not fake news, where certain 'voters' might be given a greater weighting to their votes on given topics. As with reducing ranked voting to utility maximization, the problems of using these are complex, even though the intention of statistics in general would seem to be directed to the same facilities. Like machine learning, the issue is the great 'dimensionality' of the problem, and statistical solutions don't work well. In fact, where dichotomies exist (failed praxis), statistics simply fail without the use of probabilistic techniques such as expectation analysis. A system for handling all of this type of consensus mechanisms is on the way. See Patent US20140075004 - System And Method For Fuzzy Concept Mapping, Voting Ontology Crowd Sourcing ... - Google Patents; Patent US20140075004 - System And Method For Fuzzy Concept Mapping, Voting Ontology Crowd Sourcing ... (2nd pointer is to the list of projects that were required to acknowledge the patent as prior art) .

One aspect of interest regarding the edge of statistics mentioned is that in a causality based world (see 'The Book of Why'), the causality must still be addressed even if the statistical approaches don't seem to work. Answers from the two may disagree (where 'common sense' seems to be).

>>>> Borda: "My method is made for honest men!"

This is why it would miserably fail. We live in a fallen world. We would like to live in a rational one. We do not. We will not until irrational behavior is punished in some horrible fashion. Preferably punished by the Darwin Gods w/o any human intervention that irrational monkeys with car keys can blame.

I see two problems conflated here: (1) how to combine many individual utilities, and (2) how to efficiently extract information about those utilities from each voter.

In this view, a particular voting system is just a way to collect information to build an accurate model of the voter's utility, which would then be used in some simple way. Of course, actually reducing something like ranked voting to utility maximization would be hard. But that's not a point against this perspective.

Problem (1) is presumably solved by simple utilitarianism though there are still some questions, e.g. about how to make utilities of different people comparable. I think we usually say "let all utilities be positive and let them sum to 1", but that's not necessarily correct. E.g. Quadratic voting might be an attempt to solve this problem differently.

Problem (2) is the part where we worry about whether the system invites honest voting, or whether the voters will understand it.

One issue (2) should care a lot about, that you didn't mention, is the amount of information extracted. It doesn't matter how cleanly a system works, if it doesn't extract much information from the voters about their preferences. I.e. a high VSE, presumably achieved by building a good model of the voter's utility, is the only thing that matters, while the 5 problems you listed are of little practical interest.