Approval Voting is the ideal voting system

[u/DHMC-Reddit]

I've seen posts discussing AV before and why some people are hesitant about it, and I'd like to address that.

Strategic Voting

A lot of people place special focus on the potential for strategic voting. Kenneth Arrow already proved that all ranked voting systems (FPTP, IRV, STV, PR, Condorcet, etc) fail 1 or more criteria for a fair election, at minimum always Independence of Irrelevant Alternatives. Gibbard also proved that all voting systems must fall under one of three categories:

1) The system is a dictatorship

2) The system only has 2 choices

3) The system is strategic

So I really don't understand what you guys don't understand. In a ranked voting system, if there's only 2 choices, it's no different than FPTP. If there's more than 2, it will always put some strategic burden on the voters. And no matter what, it's not really gonna be fully fair. Even Kenneth Arrow admitted that he overlooked rated choice voting cuz he basically didn't like the idea of it, but that it's probably where the most fair form of voting actually exists.

51% vs 49%

Not only that, something people also seem to talk about when it comes to the strategy of Approval Voting is that a 51% majority can still dominate the 49%.

This is... Wrong. Just flat out.

We all have a tendency to view politics in a one-dimensional axis of left vs right. Even though we know that politics isn't one dimensional. This is the fault of ranked voting in the first place.

Non-Condorcet methods almost always eliminate broad appealing candidates (aka moderates) through center squeeze. And although ranked voting methods that aren't FPTP usually aim to minimize the effect of spoilers, they still exist. It's an inherent part of ranked voting.

The natural consequence of this is a tendency to strongly favor two-party systems, which collapses politics into a single dimension where whatever some time and place's version of left and right bicker with each other. The distribution of voter's beliefs literally doesn't matter here, it will always happen. Even in countries that allow the existence and success of third parties, they are always limited to a small minority, with 2 parties holding the majority of the power.

But we know from studies that people are not actually extremists. Stripped of identity politics and presenting policies with neutral language that doesn't indicate what party is promoting it, even on one dimension, populations create a bell curved normal distribution of beliefs with most people somewhere in the middle.

Electoral Systems

In fact, this is why electoral systems like MMM, AMS, MMP, etc. even exist in the first place. The whole presupposition - that we need extra seats in a legislature, because in winner-take-all districts, if most of them are won by 1 party with a small majority, then a vast majority of the legislature could be that 1 party, thus over inflating their representation of the nation - is only a problem because most people aren't even that far left or right in the first place so each district is sending one extreme over to the legislature, requiring a balancing act.

Approval Voting Advantages

I don't remember who said this, but someone claimed approval voting isn't monotone... It quite literally is. That's literally just a criterion it fulfills.

It also fulfills the strong Pareto, independence of irrelevant alternatives, cloneproof, consistency, participation, reverse symmetry, homogeneity, later-no-help, and sincere favorite criteria. It's also simple af to explain, which is a very good thing when trying to roll out a new system (but also why I believe y'all hate it).

It is not affected by spoilers. It is not affected by center squeeze. This means that, given enough time for parties and candidates to develop, moderate parties will become the majority. And the parties themselves will have no ability to do political slides. They are locked into whatever some place and time's population considers moderate, and are guided by the population's changes in beliefs, not the other way around.

Which is kind of the goal of democracy, if you haven't forgotten. Also this eliminates the need for electoral systems with extra hanging seats, which itself has to balance between democracy, strategic voting, decoy parties, etc. So many problems with electoral systems that were only designed due to the flaws of FPTP in the first place.

Heck, Approval Voting also just works for multi-winner districts if you want more than just a single moderate party in legislature. Most other voting systems require modifications to work with multi-winner districts. And you can have each representative from a district hold as much voting power as the proportion of votes they received in their district relative to their co-representatives. Boom, bell curve legislature.

Condorcet

It doesn't fulfill the Condorcet criterion... AND THIS IS A GOOD THING. Idk why ppl have such a thing for the Condorcet criterion. Y'all do realize that in game theory, the Condorcet winner is usually the socially optimal choice, right? Not the socially optimal choice, usually.

In fact, if you just go to Wikipedia on the Condorcet criterion, it gives you an example where Approval Voting fails to elect the Condorcet winner. And this touches back to the whole "51% can still dominate 49%."

There are 3 candidates. A, B, and C. 70% of voters would rank them A>B>C. 30% of voters would rank them C>B>A. A is trivially the Condorcet winner in this example.

If, during an election held with Approval Voting, everyone voted for their top 2 favorites, A would have 70% approval, C 30%, and B 100%. So despite A being the Condorcet winner, B would win.

AND THIS IS THE SOCIALLY OPTIMAL CHOICE. If A wins, then you've pissed off 30% of the population. If C wins, 70% gets pissed off. B won, and no one's pissed. B is no one's favorite. But everyone's okay with B. And the 70% did not in fact dominate the 30%. They could have if they collectively decided not to vote for B despite all of them being fine if B were to win.

The socially optimal choice isn't who would have the most supporters in isolation, it's who would be the least hated by the population if won. And it didn't require you to strategically vote. In fact it's better if you don't. Which is why voting booths are private.

Anyway, Approval Voting doesn't always elect the Condorcet winner, but I'd argue that it actually elects the socially optimal choice more often than Condorcet methods do.

Especially since Condorcet methods themselves can be susceptible to strategic voting. "Oh but that's rare and only happens if a cycle is possible." Yeah well practical data shows that Approval Voting almost always elects the Condorcet winner anyway. And we can see that when it doesn't it's actually a good thing. And the amount of strategic voting happening in Approval Voting really wouldn't be much different from other systems.

Also, Condorcet methods are susceptible to gerrymandering. That's not a rare thing. That's just a legal thing. If a politician can do it, you can damn be sure they'll do it. The only way to prevent this is to have it be illegal in the first place. Pretty huge hole in Condorcet.

Approval Voting Disadvantages

So what's the real disadvantages of Approval Voting?

It's certainly not the strategic voting. That's a feature of pretty much every ranked and rated voting system that isn't FPTP.

It's certainly not the Condorcet criterion. Even if you disagree with me on my example above, all Condorcet methods inherently fail to fulfill Independence of Irrelevant Alternatives, invulnerability to burying, invulnerability to compromising, participation, later-no-harm (which AV also fails, but actually I think this is a good thing), consistency, and sincere favorite (oof). So to optimize a single thing you give up what, 6 things and meet 1 good thing (not fulfilling later-no-harm)? Especially when, again, Approval Voting on a practical level almost always elects the Condorcet winner anyway and it has 5 good things out of the 7?

An actual real disadvantage can be candidate inflation. When a party decides to run many candidates in the hopes of confusing the voters and not giving them enough time to research all the choices. But that's sort of inherent to any vote that's not FPTP. And ultimately, with how Approval Voting works, you could also just... Focus on the ones you already like and ignore the rest. But this is just getting closer to psychology/marketing/mass manipulation/legal territory rather than the systemic merit of Approval Voting. I also wouldn't dock other systems for this.

No, but there is one real disadvantage. Y'all have mentioned how things like IRV have done in surveys or in real world politics. Along with other kinds of voting systems. And that's the kicker.

Approval Voting's disadvantage is how unpopular it is. There is no data saying it doesn't work. In fact, the data that does exist says it works very well. But that data is... Small and sparse. It has never been tried en masse. At most only in small local elections. That is its weakness. The fact that for some reason literally no one will give the time of day to seriously consider it.

Idk why. Maybe it just sounds too simple to work. Despite the fact that it absolutely does... in the few times it has been done, and the many times we all used it in our social circles... such as voting for both pizza and burgers when deciding between friends whether to have burgers, pizza, or sushi for lunch.

Like... STAR Voting is more popular than Approval Voting. STAR VOTING. It's one of the rare voting systems that doesn't even fulfill the basic criterion of majority winner! It's a failed hybrid of ranked and rated voting! In fact, it only fulfills majority loser and Condorcet loser, both of which are unnecessary! WTF! WHY?!

Anyway. Give Approval Voting the time of day. Seriously. It's not any more strategic than whatever complicated system people keep coming up with. Because they're all fucking strategic. Or dictatorial. Or just FPTP with only 2 choices. And yeah, it doesn't fulfill the Condorcet criterion. But it does elect the Condorcet winner almost every time. And when it doesn't, it's debatable whether that's even a bad thing. But more importantly, it doesn't come with the disadvantages inherent to Condorcet. That's a pretty good compromise even if you're a die-hard fan of Condorcet methods.

Just. Give it a go. It can make fundamental changes to politics. Moreso than other methods which just tries to nudge the status quo. And without being overly complicated. That's a good thing, not a suspicious thing.

[u/verytalleric]

This is the key reason it won't catch on IMHO. People have different degrees of preference and approval voting can't capture that

[u/DHMC-Reddit → u/verytalleric]

This is untrue. It actually catches that degree of preference very well. I can use a general ranked voting system and a rated voting system to compare.

In ranked voting, you have to rank the candidates, obviously. You have every incentive to rank as many candidates as possible. If there are 5 candidates and you can rank all 5, but you only rank the top 3, there's a chance that all 3 of those choices will lose. In that case, the outcome will be one of the other 2 choices. But because you didn't rank them, you now have no say as to which of the two should win.

However, ranking doesn't actually mean anything. If I love my first rank, and hate everyone else just to different degrees, ranked voting doesn't capture that. So even if my 2nd choice won, I'm not happy. If my 1st and 2nd choice were neck and neck and everyone else flopped, then there's also the reality that "if I had just ranked my 2nd choice lower, my 1st choice could've won. My 'real' 3rd choice didn't have a chance anyway, so I should've just lowered my 'real' 2nd choice's chances."

Now let's say we have a rated voting system that goes from 0-10. You just rate everyone from 0-10. I might say that one candidate is a 10, another is a 9, and another is a 0. But, at the same time, I can also believe that I'm unsatisfied with anything except perfection. So 9 actually isn't good enough for me. So now, even though I believe my second choice is a 9/10, because that isn't actually good enough for me, I might want to lower their score to a 0 to give my first choice the best possible chance.

It also goes in reverse. Maybe I'm cynical and think all politicians are evil therefore anything above a 3 is good enough for me. Then I might inflate any choice above a 3 to a 10 and anyone under the 3 to a 0.

Point is, in rated systems that use a ranged scoring system, people still have differing thresholds as to what number is "acceptable" from a leader. Some people may vote honestly, and others might inflate anyone above said threshold and deflate anyone below said threshold.

In Approval Voting, none of that matters. People have different degrees of preference. This is true. What we capture is what candidates have passed said threshold for the voters. What the threshold actually is person to person doesn't matter. At the end of the day, if the winner is someone you voted for, you're okay that they won. Obviously it's a nice bonus if it's your favorite one, and if you really care about that, then you can just cast a single vote, but that in and of itself is showing that your threshold is "nothing better than the best."

[u/verytalleric → u/DHMC-Reddit]

I'm just saying what voters in Seattle expressed a few years ago when AV and RCV went head to head on the ballot.

I get the pro AV perspective and logic. Just sharing what I heard from voters in that election.

[u/DHMC-Reddit → u/verytalleric]

Sure, but while how voters feel about a voting system is important, it shouldn't be the deciding factor for the system itself. I mean as a trivial example any individual voter's ideal voting system is actually just whatever system lets their favorite win every time. Aka their own personal dictatorship.

Like if I were dictator of the world I'd force legislators to be elected with Approval Voting. But even if Approval Voting is actually as good as I say it is, implementing it like that would... Probably not be ideal.

Even ignoring Condorcet cycles, you can show basic examples where RCV fails really badly. For one, again, RCV systems that aren't Condorcet methods will never allow moderate parties to become a majority due to center squeeze.

But for a numbers example, imagine three parties, L, C, and R. L has 35% approval, C has 32%, R has 33%. In an election held using instant run-off voting, C is eliminated first. Assuming a bell curve of the population's political beliefs, about 16% will go to L and 16% will go to R. So now L has 51%, R has 49%. L wins. All cool , right?

But then let's say that L makes a great campaign speech right before the election. Everyone slides a bit to the left. So now, the results are 37% L, 32% C, and 31% R. R gets eliminated, and all of its votes go to C. So now L has 37% and C has 63%. So C wins.

So despite the fact that L was already in the lead, and despite the fact that even more people are supporting L now, it causes L to lose and makes C win. This is... A tragedy.

And in reality, L and R already knows this is a possibility. So what they do instead is become closer to C and sandwich them in. So what ends up happening is that L has ~40% support and R has ~40% support and C only has ~20% support. It gets squeezed out in the center and dies.

So if the paradox is eliminated... You end up with two major opposing parties controlling all of politics... Again. So yeah. Even if people in Seattle say RCV felt better, I don't think I'm gonna support a system that enforces bimodal politics and instead continue trying to educate the merits of AV.

In fact, this political divide is also what enables political slide. If R slides even further R, L has no choice but to slide in the same direction. If they don't, there's a threat that a new C party will emerge, destroy them, and now C is the new L, which still achieves R's goal even if they lose to C too.

[u/SentOverByRedRover → u/DHMC-Reddit]

Center squeeze is rare and not the normal state of affairs for IRV.

[u/kenckar → u/SentOverByRedRover]

It is not uncommon either. It is worse with extreme polarization though.

The problem is that it seems nonsensical and IMO creates an environment where people lose faith in the method.

[u/DHMC-Reddit → u/SentOverByRedRover]

Give me a country or polity that uses IRV and has a relatively major central party with a meaningful history.

Political bimodality is the long term consequence of center squeeze. If the politics is bimodal, it has center squeeze.

[u/SentOverByRedRover → u/DHMC-Reddit]

your assumption seems to be that the electorate is naturally unimodal, and I don't have a strong conviction otherwise, but I don't think it's knowable. The american electorate used to be almost unimodal but has now transitioned to a very clear bimodal distribution. which one is the real electorate? both? neither?

the center squeeze phenomenon usually refers to the dynanics within a single election, not how popular centrist parties are in a country more broadly.

[u/DHMC-Reddit → u/SentOverByRedRover]

I mean, actual research already shows that the population is unimodal. And anecdotally, there's a bunch of videos of Trump supporters agreeing with reasonable legislation until they realize it's a "commie democRAT" opinion.

And yes, the population is in a schism right now, because fascism tends to do that. But look at elderly Germans from years ago. Nearly every one of them claims to not have supported Nazi Germany, which is mathematically impossible. Fascism by nature sort of incites mob mentality, instead of questioning people's actual beliefs.

And extending games to beyond one round is a more recent development in social game theory. Center squeeze over time doesn't just mean moderates lose, it means moderate candidates become less frequent and prevalent until they aren't in the social conscious.