[EM] IRV vs Plurality

[Jonathan Lundell]

On Jan 13, 2010, at 5:02 PM, robert bristow-johnson wrote:

> 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?

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.