[EM] IRV and Plurality

[Kevin Venzke]

Chris,

Good points.

 --- Chris Benham <chrisbenham at bigpond.com> a écrit : 
> For a start I think all  good  election methods  should allow and be 
> able to handle  the voter fully ranking all the candidates. On being 
> offered a voter's full ranking a method should either respond :
>  (a) "Fine, I can handle that, that's all I need"  (ranked ballot 
> or
>  (b) " I will accept that and probably that  is all I will be interested 
> but  NOT
>  (c) " I can't handle that and I won't accept it. I  will only accept 

Myself, I would insist that an election method be able to accept an Approval
ballot as valid, i.e., equal rankings in first place.  So I would fail IRV
here.

And I don't just insist on that in order to be a pain.  Suppose I don't trust
or understand the electoral method.  I would rather decide before voting who I
am willing to back, than have my strict rankings processed in some strange way
which may, as far as I know, lead to an inferior outcome for me.

Although, I suppose I would also have to require that the method not penalize
my candidates because of how many I tied in first (e.g. with points averaging).

> My three most fundamental standards:
> 1. Condorcet Loser:
> 2. Majority Favourite:
> 3.Mutual Majority
> 4.Monotonicity:

I too would add Independence from Clones.  Although IRV technically meets this,
the IRV disaster scenario to me seems to suggest a related problem, namely:

> The Lesser of  Two Evils problem.

You make a good case that IRV>Plurality in this respect, but I still think it's
unacceptable.


Kevin Venzke
stepjak at yahoo.fr


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