simonthefox

Agreed about preference to approval. My problem with IRV isn't about strategic voting though; I think predicting the outcome is too complex to be concerned about that. The worry that I have is that a voting method that encourages candidates to move public opinion away from them will lead to weird outcomes and undermines public trust. I think the 2000 election had an example of this in plurality voting, where republicans campaigned for Nader hoping to split the vote. In IRV I worry that we'll see similar effects, where candidates campaign for opponents because they think it will give them a tactical advantage. Aesthetically that doesn't sound "fair" to me, and my worry is that weird behavior like that undermines trust in the system.

I'm not totally convinced it's better than plurality. The link I shared shows some effects that I see as pretty disqualifying in a voting system. Beyond that, vote spoilage tends to increase with ranked systems in a way that is also pretty concerning, given that complex ballots have been used as tools of voter suppression in the US in the past. I'm all for changing away from plurality voting, but I think it's worth taking a more critical look at the results IRV produces.

I'm actually working on a follow up to build interactive yee diagrams for IRV (version of ranked choice that's getting popular in the US), but Ka-Ping Yee already has a post with some static versions. IRV has some really unpleasant effects that these diagrams help make visible. For instance, in some cases a candidate might want to actively move public opinion away from their position because it makes it more likely that they would win. http://zesty.ca/voting/sim/