[EM] Irrelevant Ballots

[C.Benham]

Toby,

A while ago some-one coined the "Blank Ballots Criterion" that just said 
that the result shouldn't change if we add (or remove) some
"blank ballots".

But it struck me that a method that breaches this in spirit would 
usually meet the letter of it by simply refusing to count such ballots
as "valid".

So I coined "Irrelevant Ballots Independence" that just said that if we 
add some ballots that do nothing but plump for some candidate
with fewer above-bottom votes than any other candidate and that is 
ignored or not voted above bottom on all the other ballots then
the result shouldn't change.

It is failed by Bucklin and tends to be failed by methods that use 
arbitrary percentage thresholds of all the valid ballots as part of their
algorithms.

Chris Benham


On 11/9/2016 8:20 AM, Toby Pereira wrote:
> I've noticed people (mainly Chris Benham I think) talking about 
> "irrelevant ballots", and I just wanted to clear up the definition 
> that people use. My intuitive understanding is that a ballot is 
> irrelevant with respect to candidates A and B if it ranks/rates them 
> equally or doesn't rank/rate them at all. So if A is elected over B 
> then the addition or removal of any such ballots would never cause B 
> to be elected over A.
>
>
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