What's great about RCV (not IRV specifically) is that if the ballot data sets are retained, you can write software to recount them using other RCV algorithms. I'm curious when we'll next have a Condorcet Winner that isn't the IRV winner.
That theorem effectively says that all sensible voting systems will in certain conditions allow a voter to gain a better outcome by voting insincerely (i.e. tactically). However, it doesn't say how easy it is for a voter to determine the correct tactical vote to make, so potentially a voter would need perfect information about all the other votes cast in order for their tactic to succeed.
We’ve seen surprise results where an obscure candidate has won when too many top choices split the first choice votes and someone relegated to the floor vacuums up all the throwaway votes (people think they have to “spend” all their votes)
That’s the point. The compromise candidate won. If the top candidates had spent less time mud slinging they may have remained in others’ top two or three.
I don't have a strong preference between approval and RCV. But I think people closer to politics would. Being able to "be behind" one candidate is a meaningful promoter of civic engagement; forcing that decision is deeply entrenched in our politics.
That makes approval voting a tougher sell for implementation than RCV. Given how much better RCV and approval voting are than FPTP, it seems sensible to go with RCV.
That's not the phase of implementation that's difficult with any of these systems. It's getting the rules changed. Approval voting changes civic engagement in a fundamental way. (It also has much less real-world data behind it.)
Approval voting was passed by a 2-1 landslide majority in both Fargo and St Louis. Public opinion research by the Center for Election Science shows random American voters are much more supportive of approval voting than IRV, relative to the status quo. By a huge margin.
Agree IRV isn't the perfect system. But we have the downsides of being broadly explicable (Condorcet method's weakness), continuous with existing civic culture (approval voting's weakness), squeezing the centre (RCV/IRV's weakness) and being better than autocracy (plurality's weakness).
With some irony, the game of reforming voting systems is itself a plurality mechanism. IRV, re-branded as RCV, has taken off. It has precedence. The distance between each of RCV's competitors and it is dwarfed by the distance between each of them and FPTP. Given that, unifying around the winning "candidate" makes sense.
Put another way, bringing up approval voting in an IRV vs. FPTP discussion favors FPTP. If one wants a world in which approval voting reigns, I think it would be easier to get there with IRV as an in-between.
Any system other than plurality allows a candidate with more first place votes to beat one with fewer. Any system other than plurality or majority/runoff allows a candidate with fewer first place votes than the second place.
But, much as I dislike IRV, I’m rather skeptical of the “winner should always be one of the top two by first-place vote count” criteria suggested.
OTOH, using any ranked ballots method, I can see an argument to do a wide open “primary” using the method and then if the winner is not also the majority first-place winner doing a separate “runoff” election using the same system of, say, 5 runoff candidates, determined as:
(1) the candidate that won using the ranked-ballots voting method selected
(2) any of the top two by first place votes not selected by (1)
(3) the first candidate elected by the selected ranked ballots method when the candidates admitted to the runoff by (1) and (2) are disregarded, plus enough candidates elected by the same method disregarding all previously-admitted candidates to complete the pool of 5 candidates.
The idea being to deal with the risk of “candidate was elected due to insufficient exposure and vetting” risk, without fundamentally compromising the desirable behavior of the selected ranked-ballots method.
Why do you consider that the "wrong" outcome?
> We’ve seen surprise results where an obscure candidate has won when too many top choices split the first choice votes and someone relegated to the floor vacuums up all the throwaway votes (people think they have to “spend” all their votes)
I think its an understandable concern under any single round ranked-ballots method where you arr likely to have a large pool of cnadidates. But it can be simply remedied with a two-round system using the same method iterated to select a manageable pool of candidates (possibly gating in the top couple first-place vote getters even if they otherwise wouldn’t be in the top) for the runoff round, which still uses the same ranked-ballots method with more confidence that all the candidates have been vetted because there is a narrower field.
This keeps the integrity of whatever ranked-ballots method is chosen while avoiding the (small, but not nonexistent) risk of winning by flying under the radar.
Commonly what's done is that we truncate the ballot and only allow people to express, say, 5 preferences.