[EM] Ballot design (new simple legal strategy to get IRV)

[Kristofer Munsterhjelm]

On 10/11/2015 02:23 PM, Juho Laatu wrote:
>> On 11 Oct 2015, at 15:11, Kristofer Munsterhjelm
>> <km_elmet at t-online.de> wrote:
>> 
>> On 10/11/2015 01:06 AM, Juho Laatu wrote:
>>> 
>>> Bias-lessness is achieved in Finland by inviting representatives
>>> of
>> all parties to take part in the vote counting process. I guess the 
>> tradition is to not to even start making biased interpretations.
>>> 
>>> STV is unfortunately not as summable as e.g. Condorcet. One may
>>> lose also some privacy and introduce some risk of coercion and
>>> vote buying by recording and distributing ranked votes to the
>>> central authority (and who knows even publishing them). I have no
>>> good foolproof solution for that right now. Risks to be estimated
>>> and appropriate protective measures to be taken (or just stay in
>>> some simpler methods).
>> 
>> That brings to mind what I'd call a great open question: is the
>> Droop proportionality criterion compatible with summability? I
>> suspect not, and I suspect that a proof would make use of a
>> pigeonhole principle. I don't have much beyond that hunch, though.
> 
> Do you mean Droop proportionality with ranked votes? I'm thinking
> about a voter who votes A>B>C>D>E, where candidates A, B, C and D can
> not win. To pass the vote to E, the vote probably has to be stored as
> it is.

Yes, I was thinking of ranked ballot DPC. But it's a bit harder than
that because the single-winner analog, mutual majority, is compatible
with summability even though (if I recall correctly) inferring the whole
mutual majority set isn't. That is, summable methods can pass mutual
majority, but they can't let you know the whole minimal mutual majority set.