No electoral method is perfect and there are problems with Instant runoff ranked ballots. Look up "Favourite Betrayal" as a problem where ranking your most favourite incorrectly can accidentally result in your least favourite winning.
Of course just because there are technically flaws, doesn't mean it's not an improvement over the status quo.
Instant Runoff Ranked ballots are particularly well suited for electing a single position like a Mayor or President. Given that it's still a majoritarian system like First Pass the Post, it's a much more questionable system to use for other things like electing a parliament.
I think IRV at least has fairly unpredictable failure cases, which means they can't be exploited.
I remember seeing a 2D chart representing voter preferences on the X and Y axis, coloured by who wins under those preferences (and some symmetry-breaking assumptions). Some systems showed clear biases towards certain outcomes. IRV had a pretty symmetric shape but with a splotch in the middle that was a random jumble of different colours - an unpredictable, chaotic outcome.
> Of course just because there are technically flaws, doesn't mean it's not an improvement over the status quo.
The problem IMO is when there's better options but it's hard to get people to care enough to switch systems again. I'm hoping Ranked Robin can catch on so at least places that went to IRV can switch to a better system without new ballots.
STAR Voting (Score Then Automatic Runoff) works in two stages:
1. Voters score candidates from 0 to 5.
2. The two candidates with the highest total scores become finalists.
3. The finalist preferred by more voters wins.
So it combines score voting and runoff. Meaning it favors centrist candidates that are prefered by most people over somebody that can turn out the base.
Depends on which ranked system. IRV has a lot of issues that other systems (like STAR, my personal preference in voting system, or Condorcet methods for instance) address much better. Non-monotonicity in particular seems like a bad property of a voting system, so I'm confused that IRV is so popular recently.
> Non-monotonicity in particular seems like a bad property of a voting system, so I'm confused that IRV is so popular recently.
Same here. The idea of lobbying for a voting system where your vote for a candidate might hurt them, or where you might be better off not voting at all than expressing your honest preference is bizarre to me. If IRV was the only alternative, sure, but we have multiple other systems which don't have as bad tradeoffs. STAR or Ranked Robin would be so much better, but the Equal Vote Coalition doesn't seem to have the power behind it that FairVote does.
One reason IRV is popular is that it has extensive use in other countries (Australia, Ireland). It's not revolutionary but it's an improvement and nothing terrible has happened.
STAR has been used approximately nowhere. STAR is also one of the few seriously advocated-for voting methods in which it's possible for the first choice of a majority to lose, although that isn't likely to happen in practice.
Ranked voting and runoff systems seem to have nothing but positives yet adoption is still lacking for some reason.
No electoral method is perfect and there are problems with Instant runoff ranked ballots. Look up "Favourite Betrayal" as a problem where ranking your most favourite incorrectly can accidentally result in your least favourite winning.
Of course just because there are technically flaws, doesn't mean it's not an improvement over the status quo.
Instant Runoff Ranked ballots are particularly well suited for electing a single position like a Mayor or President. Given that it's still a majoritarian system like First Pass the Post, it's a much more questionable system to use for other things like electing a parliament.
I think IRV at least has fairly unpredictable failure cases, which means they can't be exploited.
I remember seeing a 2D chart representing voter preferences on the X and Y axis, coloured by who wins under those preferences (and some symmetry-breaking assumptions). Some systems showed clear biases towards certain outcomes. IRV had a pretty symmetric shape but with a splotch in the middle that was a random jumble of different colours - an unpredictable, chaotic outcome.
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> Of course just because there are technically flaws, doesn't mean it's not an improvement over the status quo.
The problem IMO is when there's better options but it's hard to get people to care enough to switch systems again. I'm hoping Ranked Robin can catch on so at least places that went to IRV can switch to a better system without new ballots.
In Star Vote Favourite Betrayal still exists, but its very rare.
The issue is that you can't have 'Later No Harm' and 'Favorite Betrayal' at the same time.
Star Vote scores high on both but it can't be perfect.
See: https://link.springer.com/epdf/10.1007/s10602-022-09389-3?sh...
PS for those that don't know:
STAR Voting (Score Then Automatic Runoff) works in two stages: 1. Voters score candidates from 0 to 5. 2. The two candidates with the highest total scores become finalists. 3. The finalist preferred by more voters wins.
So it combines score voting and runoff. Meaning it favors centrist candidates that are prefered by most people over somebody that can turn out the base.
Depends on which ranked system. IRV has a lot of issues that other systems (like STAR, my personal preference in voting system, or Condorcet methods for instance) address much better. Non-monotonicity in particular seems like a bad property of a voting system, so I'm confused that IRV is so popular recently.
> Non-monotonicity in particular seems like a bad property of a voting system, so I'm confused that IRV is so popular recently.
Same here. The idea of lobbying for a voting system where your vote for a candidate might hurt them, or where you might be better off not voting at all than expressing your honest preference is bizarre to me. If IRV was the only alternative, sure, but we have multiple other systems which don't have as bad tradeoffs. STAR or Ranked Robin would be so much better, but the Equal Vote Coalition doesn't seem to have the power behind it that FairVote does.
One reason IRV is popular is that it has extensive use in other countries (Australia, Ireland). It's not revolutionary but it's an improvement and nothing terrible has happened.
STAR has been used approximately nowhere. STAR is also one of the few seriously advocated-for voting methods in which it's possible for the first choice of a majority to lose, although that isn't likely to happen in practice.
_Is_ it lacking? Most democratic systems use some form of PR and/or runoffs.
First past the post is beneficial for establishment parties.
Indeed. It tends to reinforce a two-party system. Anyone who votes third-party gets accused of 'wasting' their vote.
Preferential/ranked choice voting allows people to vote third-party while still expressing a preference for one of the majors.