At 05:03 AM 12/28/2008, Kristofer Munsterhjelm wrote:
Say that Approval distorts towards Plurality. What does Condorcet distort towards -- Borda? "Let's bury the suckers"? If people are strategic and do a lot of such distortion, wouldn't a runoff between Condorcet (or CWP, if you like cardinal ballots) and something resistant to Burial (like one of the methods by Benham, or some future method), be better than the TTR which would be the result of Approval-to-Plurality distortion? If people stop burying, the first winner (of the "handle sincere votes well" method) will become more relevant; if they don't, the latter (strategy resistant Condorcet) will still be better than Plurality, I think.
I'm certainly open to other suggestions. However, practical suggestions at this point should be relatively simple methods, which is why I'm suggesting Bucklin. Bucklin distorts toward Plurality. But the protection of the favorite is substantial enough that many voters *will* add votes; and historically, in municipal elections, many did. Plenty enough to impact results.
(FairVote points to a long primary election series in Alabama with only 11% of ballots using the additional ranks, but that seems to be very low compared with the municipal elections, it's not clear what the cause was. And my guess is that IRV would have shown quite the same phenomenon.)
Now, that's probably a very complex system: first you have to define both the sincere-good and the strategy-resistant method, then you have to set it up to handle the runoff too. But it's not obvious how to be selfish in CWP (except burying), whereas it's rather easy in Range (->Approval, or to semi-Plurality based on whatever possibly inaccurate polls tell you). This, in itself, may produce an incentive to optimize. "I can get off with it, and I know how to maximize my vote, so why shouldn't I?"; and then you get the worsening that's shown in Warren's BR charts (where all methods do better with sincere votes than strategic ones). In the worst case, the result might be SNTV-like widespread vote management.
Let's keep it simple to start! Bucklin has some interesting possible variations: Condorcet analysis could be done on the ballots, and one runoff trigger could be conflict between the Bucklin winner and a Condorcet winner. Bucklin is a very simple method to canvass, just count and add the votes. You can look at a summary of all the votes in each position and use it. Preferential analysis is different, and requires the matrix, but at least that can be summed!
Bucklin/Condorcet/Majority required runoff would still be simpler to canvass than IRV.
The most common "voting strategy" would be truncation, which simply expresses something that is probably sincere! (I.e., I prefer this candidate strongly to all others, so strongly that I don't even want to allow competition two ranks down!)
That there is a runoff would probably encourage more truncation; however, supporters of truly minor candidates can make their minor candidate statement and prevent compromise failure in the primary. They will continue to add additional preference votes, and it is this that will generally prevent Center Squeeze.
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