[EM] RE : Re: A few concluding points about SFC, CC, method choice, etc.

[Kevin Venzke]

Hi,

--- Abd ul-Rahman Lomax <abd at lomaxdesign.com> a écrit :
> then Range still fails 
> SFC, and it is easy to construct scenarios where it does so by 
> choosing a winner who is clearly "better" for society and for the 
> members of society individually, than the Condorcet winner.
> 
> This is because of preference strength. If the CW is preferred, by a 
> majority to a candidate A by a majority with a very small preference, 
> such that, for practical purposes, these voters will be equally happy 
> with the election of the CW or A, and a minority of voters strongly 
> prefer A, such that they will be happy with A and seriously unhappy 
> with the CW, it is quite clear that A should win. A makes *everyone* 
> happy, the CW in this situation only makes a bare majority happy.
> 
> Thus, we conclude, the Condorcet Criterion *must* be violated in some 
> elections by an optimal method, and thus this theoretical optimum 
> method must fail the criterion and others similar to it, such as the 
> Majority Criterion and SFC.

I agree with this, although I don't think this theoretical optimum
method exists. If it does exist I suppose it's pretty complicated.

> Of course, we need a definition of "optimal." I've been suggesting 
> that it should be explicit.

I thought you already defined "optimal" above when hinting at utility.

> Too often, when we consider methods by 
> election criteria, we assume that a criterion is desirable, entirely 
> apart from whether or not it chooses the optimum winner.

I would guess that most of our criteria *do* coincide with higher 
utility. All things being equal you couldn't expect that a method that 
fails majority favorite would produce higher utility.

There are other issues besides utility of course... There's the question
of what the public will accept and understand how to use, and there's
all the questions of how to give the voter incentive to vote sincerely.

> It's 
> *assumed*, very easily, that the majority choice is the optimum 
> winner -- and therefore it is desirable to satisfy the Majority 
> Criterion -- when this is certainly not clear enough to be reasonably 
> an axiom.

I think it's actually clear that the majority favorite isn't necessarily
the SU winner. I don't think it follows from this that it isn't desirable
to satisfy MF. It depends on what alternatives you have.

> Any person or business which makes decisions failing to 
> consider the strength of preferences will soon run into trouble....

An individual person has a great advantage in measuring preference 
strengths.

Kevin Venzke


	

	
		
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