[EM] Ultimate SPE Agenda Processing: Sink Swap Bubble

[Kevin Venzke]

Hi Forest,

Le samedi 1 avril 2023 à 10:31:08 UTC−5, Forest Simmons <forest.simmons21 at gmail.com> a écrit :
> Here's an example of another standard test case for Sink Swap Bubble ("Bubba" for short).
> 
> 48 C
> 28 A>B
> 24 B (sincere is B>A)
> 
> The smallest faction has thrown the sincere CW under the bus ... knowing that most Condorcet
> methods, including classical wv methods like Ranked Pairs, would break the resulting ABCA
> beat cycle at the weakest defeat A>B, leaving B as the winner.

> Bubble changes the order to B<A<C ... the finish order of the method ... thus disappointing
> the defecting faction with a finish order polar opposite to their sincere preferences ... 
> 
> When will they learn that you cannot mess with Bubba?

I've said this before, but I'm not a fan of this kind of method because, what if you're
wrong about the sincere preferences? Then by electing C, you're actually punishing the A>B
voters for not using compromise strategy. This muddies the water as to what behavior
"chicken resistance" is actually incentivizing.

Can we really be so confident that an unstated preference hides a specific meaning?

I also ask what you think of this modified scenario:

48 C
28 B (sincere is B>A)
24 A>B

I guess you'll say that B is allowed to win because B is both the sincere and voted CW. But
that's a different question from what a "chicken-resistant" method *should* do, if we
really believe in this approach.
 
Kevin
votingmethods.net