It’s my favourite single-winner, because I’ve looked at all the others and decided the downsides of the others outweigh the downsides of IRV. But I’d still rank any proportional system much higher than IRV. And ironically, STV (which is a multi-winner version of IRV) is among my least favourite, due to its relatively limited almost quasi-proportional nature.
Later-no-harm is meaningless. It’s basically a “did you vote for this person? They might win”
Well, no. It’s that by adding more candidates to your ballot who were not your favourite choice, you could actually decrease the chance your favourite candidate wins. It’s that a tactical dishonest vote can be more optimal than an honest vote. And that’s bad. That’s bad in the real world.
I know IRV fails in a lot of theoretical ways. But when it’s used in the real world that just doesn’t matter. I mean, it could theoretically matter, but with how real people actually vote, it doesn’t. I explained how that happens earlier.
This brings up the issue of ballot exhaustion again
Definitely a problem. And unfortunately I’ve seen it matter, with some candidates dishonestly promoting “just vote 1” in the closest thing Australia has to the type of voter discouragement campaigns that are so rife in America. Federally and in my state, Australia uses compulsory preferential voting. You have to number every candidate. This eliminates the exhausted ballot problem. Our local council elections are where exhaustion becomes a problem. The solution isn’t to move to an inferior voting system, it’s to use the same compulsory preferential system used in other elections.
We know you like number 1, but number 2 could be anything between Jesus and Hitler. There’s no information there, just that you like them less than 1.
This is a feature, not a bug. The fact that you’re thinking about it as a disadvantage says a lot to me about why you like cardinal systems. I fundamentally disagree.
It doesn’t matter if I love one candidate, like another, and hate the third, or like one, dislike another, and hate the third. What matters is who my vote helps elect. And I want the first one to win, or if they can’t, I want the second one to win. And that’s what IRV perfectly represents. In a cardinal system, if I vote 5, 2, 1, as is my honest preference, all that does is help my least favourite candidate win if my favourite doesn’t, compared to if I voted 5,5,1, or 5,4,1. That’s how any cardinal system inevitably devolves into approval. And again with approval, I lose the ability to distinguish preference. You say it’s bad that my second preference could be Jesus or Hitler, but at least with IRV I can clearly say I like Jesus more than Hitler, instead of just saying I “approve” of both because the only remaining option is Pol Pot. At the point where I know Jesus isn’t going to win, it doesn’t matter how much more I prefer Hitler over Pol Pot. I just want to ensure Pol Pot doesn’t win. Ordinal voting better represents how a rational voter thinks about the candidates than cardinal voting does. And that’s why it’s better.