[EM] Kevin, SFC

[Michael Ossipoff]

Kevin said:

Hi, By the way, you can also ensure a method satisfies SFC by having it 
comply with this votes-only criterion: "If more than half of the voters rank 
A over B, but there is no majority of the voters ranking some third 
candidate over A, then B doesn't win."

I reply:

First, does Kevin’s criterion apply only to rank methods? My criteria apply 
to all methods.

Or if we change the verb “rank” to “vote”, and apply the criterion to all 
methods, then Plurality meets Kevin’s criterion.

Kevin continues:

Personally I feel that SFC *is* more about avoiding an embarrassing result, 
than about providing a strategy guarantee

I reply:

Kevin can personally feel anything that he wants to. And if he chooses to 
not tell us why he personally feels it, that’s fine too. It’s pretty obvious 
that SFC provides a strategy guarantee: The majority that it refers to can 
defeat whomever they like less than the CW, by doing nothing more than 
voting sincerely, and without knowing who the CW is, as long as no one 
falsifies.
.
And remember that it, though the criterion’s premise stipulates that no one 
falsifies,  isn’t really necessary that _no one_ falsify. It’s enough if not 
enough falsify to change the outcome.

However, if a failure to meet SFC would embarrass Kevin, then I laud Kevin’s 
aesthetic taste.

Kevin continues:

... --- Michael Ossipoff <mikeo2106 at msn.com> a écrit : > SFC is more 
demanding than the Condorcet Criterion. Hm, I don't think I would say 
that... You can satisfy one and not the other. And I can think of a couple 
of criteria compatible with SFC but not Condorcet.

I reply:

It’s probably ultimately a subjective individual opinion, which criterion is 
more demanding. But SFC must be more difficult to meet, since all 
pair-wise-count methods meet CC, but only the wv Condorcet methods meet SFC.

Is there a method that meets SFC but fails CC? There are certainly methods 
that meet CC but fail SFC.

Maybe Kevin and I have different meanings for criterion demanding-ness.

Mike Ossipoff