[EM] IRV vs Plurality

[robert bristow-johnson]

On Jan 13, 2010, at 7:57 PM, Jonathan Lundell wrote:

> On Jan 13, 2010, at 4:13 PM, Dave Ketchum wrote:
>
>> On Jan 13, 2010, at 4:49 AM, Juho wrote:
>>> On Jan 13, 2010, at 9:14 AM, robert bristow-johnson wrote:
>>>
>>>> it still is a curiosity to me how, historically, some leaders  
>>>> and proponents of election reform thunked up the idea to have a  
>>>> ranked-order ballot and then took that good idea and married it  
>>>> to the IRV protocol.  with the 200 year old Condorcet idea in  
>>>> existence, why would they do that?
>>>
>>> 1) The basic idea of IRV is in some sense natural. It is like a  
>>> street fight. The weakest players are regularly kicked out and  
>>> they must give up. I'm not saying that this would lead to good  
>>> results but at least this game is understandable to most people.  
>>> Condorcet on the other hand is more like a mathematical equation,  
>>> and the details of the most complex Condorcet variants may be too  
>>> much for most voters. Here I'm not saying that each voter (and  
>>> not even each legislator) should understand all the details of  
>>> their voting system. The basic Condorcet winner rule is however a  
>>> simple enough principle to be explained to all. But it may be  
>>> that IRV is easier to market (to the legislators and voters) from  
>>> this point of view.
>>
>> When there is a CW in Condorcet, the CW has won in comparison with  
>> each other candidate.  While a few may like X or Z enough better  
>> to have given such top ranking, the fact that all the voters  
>> together prefer the CW over each other should count, and does with  
>> Condorcet.
>
> 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?

--

r b-j                  rbj at audioimagination.com

"Imagination is more important than knowledge."