[EM] Remember Toby

[Juho Laatu]

On 29.5.2011, at 5.07, Kevin Venzke wrote:

> Hi Juho,
> 
> --- En date de : Sam 28.5.11, Juho Laatu <juho4880 at yahoo.co.uk> a écrit :
>>> Margins elects A here:
>>> 35 A>B
>>> 25 B
>>> 40 C
>>> 
>>> Is this going to be defensible when this method is
>> proposed? Can you
>>> argue a case for A without mindreading off of the
>> blank areas of the 
>>> ballots?
>> 
>> I guess the common assumption is that the unranked
>> candidates are considered to be tied at the last position.
>> So, vote "B" should be read "B>A=C".
>> 
>> (The intended meaning of "B" and "B>A=C" is thus the
>> same by default. Some methods may however have an implicit
>> "approval" cutoff at the end of the explicitly ranked
>> candidates. In that case vote "B" should be interpreted "B |
>> A=C" and "B>A=C" should be interpreted "B>A=C |", but
>> I consider that to be a special case. If the voter has some
>> preference between A and C (and she wants to express it),
>> then the voter should mark that in the ballot, since
>> otherwise there is no other sensible interpretation but that
>> A and C should be treated as equal. If there are so many
>> potential winners in the election that one can not expect
>> all voters to rank all potential winners, then we may lose
>> some of the information that the voters wanted to give. I'm
>> not sure if I answered properly to the mindreading point
>> here but those were my thoughts anyway.)
> 
> The mindreading point is that you are having to say "if the voters
> wanted to say something they could have said it." I'm not sure this will
> be persuasive because you can't offer an assurance that those voters
> could vote that way without risking something. This is why I suggest that
> you had better force voters to rank everyone in a margins method.

In som sense margins does this. Vote "B" gives the same result as half vote "B>A>C" and half vote "B>C>A" together. Or statistically the results are the same if all uncertain voters will flip a coin and vote either way.

> 
> In WV A and C will be considered as equal, too - it just won't count
> that voter as a schizophrenic who always feels 50% cheated no matter what
> happens between the two.

This was not an easy explanation :-).

Juho


> 
> Kevin
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