[EM] Why I think IRV isn't a serious alternative 2

Abd ul-Rahman Lomax abd at lomaxdesign.com
Sun Dec 28 13:29:30 PST 2008

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.

More information about the Election-Methods mailing list