I'm continually upset and confused by Instant runoff voting's popularity. IRV is, by my reckoning, a much inferior (and more complicated) system than other systems, like range voting or ranked pairs. And it has some bizarre properties that make me wonder if it is even worse than the traditional first-past-the-post.
One property of IRV that makes it so questionable is its non-monotonicity. This means that you can help a candidate by ranking them lower, and hurt a candidate by ranking them higher. It is extremely easy to visualize how ill-behaved IRV is in the charts on this website:
http://zesty.ca/voting/sim/
Meanwhile, ranked pairs (a "condorcet" method) has the property that, if candidate A is more popular than all other candidates pairwise, then candidate A will always win. This is _not_ true in IRV.
If you're interested in falling down the rabbit hole of electoral systems, I recommend looking at this chart that compares their properties:
https://en.wikipedia.org/wiki/Comparison_of_electoral_system...
One property of IRV that makes it so questionable is its non-monotonicity. This means that you can help a candidate by ranking them lower, and hurt a candidate by ranking them higher. It is extremely easy to visualize how ill-behaved IRV is in the charts on this website:
http://zesty.ca/voting/sim/
Meanwhile, ranked pairs (a "condorcet" method) has the property that, if candidate A is more popular than all other candidates pairwise, then candidate A will always win. This is _not_ true in IRV.
If you're interested in falling down the rabbit hole of electoral systems, I recommend looking at this chart that compares their properties:
https://en.wikipedia.org/wiki/Comparison_of_electoral_system...