I'm not convinced that instant runoff is actually better than FPTP.
Without tactical voting (and good information to support it) the first thing IRV does (along with most variations that in practice get the label "RCV", though of course this doesn't apply to all ranked methods) is to throw out the compromise candidate that everyone likes.
In the current situation, I am concerned that most people will prefer their particular flavor of theocracy to finding ways to get along (which they probably prefer to anyone else's flavor of theocracy). We already struggle with similar dynamics a bit, but it's the devil we know and I really don't want it magnified.
Even if your technical argument would be correct (it's not), you would be trying to fix the problems of democracy by purposefully skewing the vote away from the desires of the electorate. That's a bad idea because it prevents democracy from working and exposing the leaders to the unfiltered democratic will of the people; so you get unaccountable leaders that can maintain power by gaming the system instead of catering for the interest of the public.
Essentially, any power-mad dictator and authoritarian regime has some variant of this argument. Yes, we love democracy and voting, but we definitely cannot let those kinds of people vote or get elected. You are just espousing the softer version still accepted in some countries of "yes, the voting system is not ideal but it gives our side an advantage for now, realpolitik always trumps democratic principles".
Uh, no. Insofar as "the desires of the electorate" is a thing that exists, I am insisting that IRV sometimes does a piss poor job of picking it. In an election where 90% of the electorate prefers A to B, we shouldn't necessarily be picking A but we clearly shouldn't be picking B (especially with no indication of strength of preference); IRV can, and I think does in some cases that are both dangerous and realistic.
Getting a little more concrete:
Imagine a society split roughly evenly between 3 religions. Let's say 35% follow religion A, 30% follow religion B, 30% follow C, the remaining 5% belong to other religions or no religion. Approximately everyone with a religion (in our model; reality is more complicated but not sufficiently to make things inapplicable) prefers that society be organized as a theocracy according to their religion, would sufficiently accept secular tolerance, and violently opposes living under another religion's theocracy.
In this imaginary society, what is "the desire of the electorate"?
If everyone votes their honest maximal preference then the plurality says Theocracy A, which is violently opposed by 65% of the population! Picking secular tolerance over Theocracy A is not just something I (probably) prefer from the outside, but is actually preferred by the vast majority of the population over what IRV would pick!
I don't follow your example. If the religious vote according to their genuine preferences, they would pick their brand of theocracy as the first option and the secular option as the second. IRV would then eliminate two theocracies in the first round and then secularism would win by a landslide in the instant run-off.
Yes, there are games which can be played that increase the chances of some minority group in the second round, for example not listing secularism in the hope that it won't make it to the runoff. But it's a dangerous game of chicken for which the optimal strategy becomes apparent only after the results are tabulated. Alaska is a good example where even with excelent information and pooling data the Palin voters were stil unable to coordinate to skew the results. The existence of that risk is heaven and earth compared to an FPTP election which pretty much guarantees theocracy in your example.
> IRV would then eliminate two theocracies in the first round
Either I failed to communicate the situation I intended or one of us is very wrong about how IRV works.
Reducing the society to 20 people to simplify the proper language a little: We have 7 ballots that start "A;S;...", 6 ballots that start "B;S;...", 6 ballots that start "C;S;...", and one ballot that starts with "S". IRV considers the options in first place, sees that S is the least (only one person ranked it first), and eliminates that option. Which theocracy is picked will depend on things further down the list, but it will never be secularism. In the best case it will pick A, which would lose to S 13:7 in a head to head vote.
If we believe that "the appropriate compromise" between people with genuine disagreement will typically not be anyone's first choice, IRV specifically systematically excludes that appropriate compromise.
> FPTP election [...] pretty much guarantees theocracy in your example
Yes, FPTP doesn't fare better here mechanically. The advantage of FPTP (which, to be clear, I still think is terrible) is that most voters understand that they need to vote strategically and understand how to do that. IRV is often sold on removing the need to vote strategically, and it does not do that, while making the correct strategic choice more complicated than "the better of the front runners".
Sorry, I got confused about the example, you are of course correct, it's a basic center squeeze.
The IRV case here is simply a cheaper way to organize a delayed runoff; voters are usually adept at understanding the implications of strategic voting, as long as it's framed correctly: in case your preferred option does not make it to the second round, would you still go to vote, and which would be your other choice? In Europe there is a long tradition for the two round delayed runoff, but it's certainly not presented to the voters as "you can chose anybody in the order of preference and it will be magically solved by the system".
Two round is in almost any case superior to FPTP, so if you can get it by simply tweaking the ballot paper and allowing second and third choices (IRV), it's an easy upgrade.
Approval voting might be closer to a Condorcet winner in some cases, but it's not a panacea to center squeeze because it's vulnerable to honest voting. What we see in practice is a tendency to function as FPTP, as all sides have an incentive to demonize the center and train their voters to mark a single option. So, in your example, the Sunni or Shia Muslims which can't stand themselves enough to approve each other but would still prefer islam in the second round (if secularism is not available), would lose the approval vote to a well disciplined contigent of Buddhists.
IRV solves that by not providing any help to competitors in the first round, and moving the "lesser evil" decision into the second round, encouraging more honest voting. Short of some Condorcet method (which will never be practical or intelligible by the average voter), IRV is an "acceptable compromise".
> If everyone votes their honest maximal preference then the plurality says Theocracy A, which is violently opposed by 65% of the population!
I'm failing to see how that's worse than FPTP, which in practice would also result in picking Theocracy A (because the 5% representing the Secular Tolerance Party would be one of those "third parties" which get blamed for spoilers under FPTP).
I don't claim it's worse; I'm not convinced it's better. Here they behave the same, and I think it's a pretty significant failure on both their parts. If I had to argue that IRV is worse than FPTP, I'd point out that voters already know what sort of strategic voting FPTP expects of them, while IRV is often sold on the premise that voters don't need to vote strategically and so is more likely to hit those failure modes in more damaging ways as we learn... but there's a degree of devil's advocate there. I do worry that it might be worse, but I do not claim that it is.
Well yeah, in this particular instance they do. That doesn't mean they always do. For example, with the commonly-used Tennessee capital election scenario (https://en.wikipedia.org/wiki/Instant-runoff_voting#Tennesse...), IRV would select Knoxville while FPTP would select Memphis - still not quite optimal for everyone (Nashville would probably be the ideal winner in a "perfect" electoral system), but good enough for the majority and a strict improvement over FPTP.
Of course they don't always; certainly IRV is sometimes mechanically better. I believe we can construct examples where FPTP would happen to work out better given the same honest votes, although I do think they're more contrived - see below for details. I am more worried about what happens in practice, though; as I said, people understand with FPTP that they need to vote strategically and understand how to do that.
Contrived scenario for FPTP picking the Condorcet winner while IRV fails to:
Back to the "which theocracy, or do we just tolerance?" question, but now each religion has at least two candidates and secular tolerance has a bigger constituency.
FPTP picks S, sort of by chance, which is also the Condorcet winner. IRV consolidates the C votes behind C1, then the B votes behind B1, then the A votes behind A1, then discards S.
I think that works out, FPTP makes the right choice for sort of the wrong reason while IRV makes the wrong choice. But I do think the much bigger concern is FPTP-with-strategic-voting behaving better (or at least no worse) than IRV-with-whatever-happens-in-practice.
Without tactical voting (and good information to support it) the first thing IRV does (along with most variations that in practice get the label "RCV", though of course this doesn't apply to all ranked methods) is to throw out the compromise candidate that everyone likes.
In the current situation, I am concerned that most people will prefer their particular flavor of theocracy to finding ways to get along (which they probably prefer to anyone else's flavor of theocracy). We already struggle with similar dynamics a bit, but it's the devil we know and I really don't want it magnified.