This makes IRV a really bad choice. IRV results in a two-party system just like plurality voting does.
I agree that having a multi-party system might be most important, but I don’t think IRV necessarily leads to a two-party system. For instance, French presidential elections feature far more than two parties (though they’re using a two-round system rather than IRV).
Everything is subject to tactical voting (except maybe SODA? but I don’t understand that argument). So I don’t see this as a point against approval voting in particular.
I think that approval voting has significantly more serious tactical voting problems than IRV. Sure, they all violate some criteria, but the question is how serious the resulting issues are in practice. IRV seems to be fine based on e.g. Australia’s experience. (Of course, we don’t really know how good or bad approval voting would be, because it is rarely used in competitive elections.)
I agree that having a multi-party system might be most important, but I don’t think IRV necessarily leads to a two-party system. For instance, French presidential elections feature far more than two parties (though they’re using a two-round system rather than IRV).
Yeah, I know very little about multi-party systems in practice (IE why these specific countries have escaped the two-party dynamic). But it’s plausible to me that there are a few exceptions but the overall gravity of a voting system still makes a big difference. Especially in places where a two-party system is already entrenched, it’s plausible that IRV just wouldn’t be enough to dislodge it.
It’s also plausible to me that if we could do controlled experiments, we would see two-party systems arise a much higher percentage of the time in plurality-voting systems than IRV, or that it would take much longer to settle into a two-party equilibrium in IRV systems.
Also, considering French politics (and the politics of other places with multiparty systems), maybe getting rid of two-party systems is not so important as I initially thought—it doesn’t seem like multi-party politics is so much better in terms of sanity and quality of policy.
I think that approval voting has significantly more serious tactical voting problems than IRV. Sure, they all violate some criteria, but the question is how serious the resulting issues are in practice. IRV seems to be fine based on e.g. Australia’s experience. (Of course, we don’t really know how good or bad approval voting would be, because it is rarely used in competitive elections.)
I agree, and that’s why I base my opinion mostly on the statistics, which seem to favor approval. Out of the different levels of strategic voting considered, IRV’s worst-case scenario is worse than approval’s worst-case, and IRV’s best-case is worse than approval’s best-case. Granted, they have an overlapping range.
Perhaps more importantly, STAR voting and 3-2-1 voting beat both pretty decisively. Score voting (aka range voting) is best in completely honest cases, but subject to strategy, becomes as bad as approval. STAR reigns that problem in (by introducing its additional runoff), compromising some value in the completely honest case for a better lower bound in the very strategic case. 3-2-1 does the same thing even moreso, making all the scenarios roughly equally good.
Granted, these are simulated statistics, not real-world elections.
I agree that having a multi-party system might be most important, but I don’t think IRV necessarily leads to a two-party system. For instance, French presidential elections feature far more than two parties (though they’re using a two-round system rather than IRV).
I think that approval voting has significantly more serious tactical voting problems than IRV. Sure, they all violate some criteria, but the question is how serious the resulting issues are in practice. IRV seems to be fine based on e.g. Australia’s experience. (Of course, we don’t really know how good or bad approval voting would be, because it is rarely used in competitive elections.)
Here’s an argument that IRV has a pretty bad track record.
Yeah, I know very little about multi-party systems in practice (IE why these specific countries have escaped the two-party dynamic). But it’s plausible to me that there are a few exceptions but the overall gravity of a voting system still makes a big difference. Especially in places where a two-party system is already entrenched, it’s plausible that IRV just wouldn’t be enough to dislodge it.
It’s also plausible to me that if we could do controlled experiments, we would see two-party systems arise a much higher percentage of the time in plurality-voting systems than IRV, or that it would take much longer to settle into a two-party equilibrium in IRV systems.
Also, considering French politics (and the politics of other places with multiparty systems), maybe getting rid of two-party systems is not so important as I initially thought—it doesn’t seem like multi-party politics is so much better in terms of sanity and quality of policy.
I agree, and that’s why I base my opinion mostly on the statistics, which seem to favor approval. Out of the different levels of strategic voting considered, IRV’s worst-case scenario is worse than approval’s worst-case, and IRV’s best-case is worse than approval’s best-case. Granted, they have an overlapping range.
Perhaps more importantly, STAR voting and 3-2-1 voting beat both pretty decisively. Score voting (aka range voting) is best in completely honest cases, but subject to strategy, becomes as bad as approval. STAR reigns that problem in (by introducing its additional runoff), compromising some value in the completely honest case for a better lower bound in the very strategic case. 3-2-1 does the same thing even moreso, making all the scenarios roughly equally good.
Granted, these are simulated statistics, not real-world elections.