[EM] Ultimate SPE Agenda Processing: Sink Swap Bubble

[Kristofer Munsterhjelm]

On 4/12/23 14:11, Forest Simmons wrote:
> OK ... lacking an ndefeated candidate to elect ...
> 
> 1. Use the RCV ballot informatioren to construct an elimination agenda 
> ... a list of the candidates with the less favorable near the top of the 
> list, and the more favorable near the bottom.
> 
> 2.This list is to be published a week or ten days before the runoff.
> 
> 3. The runoff ballot is an official copy of this agenda with the 
> following accompanying instructions:
> 
> 4. Put a check mark next to the name of every candidate you like better 
> than any of the candidates listed below it. The check mark is an 
> abbreviation for BTAOTB "Better Than Any of the Below"
> 
> 5. Elect the highest candidate on the list that has a BTAOTB check mark 
> on more than 50% of the submitted ballots.
> 
> 6. The candidate listed last (bottom) is the default winner (when no 
> other candidate is preferred over "The Below" by a full majority of the 
> participating voters).
> 
> All registered voters should be able to  participate in this runoff, 
> even if they did not participate in the first round (the check for a 
> candidate undefeated pairwise).
> 
> It seems to me that the simplicity and importance of the runoff would 
> attract excellent participation.
> 
> Thoughts and suggestions?

It seems a bit complicated and if we suppose that voters have 
preferences among clones (i.e. don't consider them all equally good), it 
would fail clone independence.

I would think that in a multi-way election, there would be a very low 
probability that a majority would consider a single candidate to be 
BTAOTB. Majority runoffs work because there are only two candidates, so 
in the absence of ties, there's always a winner, but I don't think that 
would generalize easily to multiple candidates. (In a way, this is the 
same problem as the clone dependence one; or rather, both are effects of 
the same root cause.)

I really ought to make a variation on my strategy calculator for finding 
optimal methods with a honest runoff stage, but I have so many projects 
already...

-km