[EM] IRV vs Plurality

[robert bristow-johnson]

On Jan 13, 2010, at 8:26 PM, Jonathan Lundell wrote:

> On Jan 13, 2010, at 5:02 PM, robert bristow-johnson wrote:
>
>> On Jan 13, 2010, at 7:57 PM, Jonathan Lundell wrote:
>>>
>>> This seems to me to be a claim that is at best not self-evident  
>>> (in the sense that Pareto or anti-dictatorship, say, are). While  
>>> I'm not a fan of cardinal-utility voting systems, it seems  
>>> entirely possible to make a utility argument or rationale against  
>>> the *necessity* of electing the CW in all cases.
>>>
>>> That is, as a thought experiment, if we could somehow divine a  
>>> workable electorate-wide utility function, it's at least arguable  
>>> that the utility winner would legitimately trump the Condorcet  
>>> winner, if different, while you couldn't make a similar argument  
>>> wrt Pareto or dictatorship.
>>
>> how would you define that "utility function" metric in a  
>> democracy?  would the candidates arm-wrestle?  take a written  
>> exam? flip a coin?  what, other than majority preference of the  
>> electorate, can be such a metric in a democracy?
>
> I don't think you can, and that's a big problem for Range, it seem  
> to me.
>
> But we're talking about utility for the voter, not arm-strength of  
> the candidates.


I guess I didn't understand that the utility function was for the  
individual voter.  Yes, that *is* Range voting.  And if the value is  
restricted to binary, it's Approval voting.  Especially if you add up  
the values of a candidate for all voters (maybe we should add their  
square-roots, I dunno).

we have a choice of candidates.  only one candidate can be elected  
(single winner).  the "best" candidate means that this candidate is  
"better" than any other candidate.  if we define "better than the  
other candidate" as "preferred by more voters than prefer the other  
candidate" (it's a dichotomy, the alternative is to give it to the  
*less* preferred candidate, unless we make them arm wrestle, or take  
a written exam or something other criterion without votes), then the  
Condorcet candidate is better than every other candidate.

I guess I still haven't heard a good justification for why the  
Condorcet winner, if one exists, should *ever* be rejected as the  
elected winner.

--

r b-j                  rbj at audioimagination.com

"Imagination is more important than knowledge."




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