I was saying that I determined that both wv and Margins can�t fail FBC, with 3 candidates, if the B voters in my scenario vote A in 2nd place. That�s true, unless I made an error in the determination.

Well, with wv, if the B voters truncate, don�t vote for anyone but B, then the C voters don�t have to do anything other than rank sincerely to save B.

With that scenario, with Margins, I couldn�t find a contradiction between the inequalities that must be satisfied in order for the C1 voters to be unable to save B by ranking B equal to C, but able to save B by ranking B over C.

In fact, the Margins WDSC failure example that I posted a few days ago is also a Margins FBC failure example, because the C voters can�t save B by ranking B equal to C, but can save B by ranking B over C. They can get their best outcome, B, only by voting B over their favorite.

So Margins fails FBC, and has an FBC failure example with 3 candidates.

Unless I made an error, there�s no wv FBC failure example with 3 candidates.

Maybe wv doesn�t fail FBC, but it really seems to me that someone once sent to me an example in which wv failed FBC. Maybe that example wasn�t valid for some reason, and wv passes FBC. I don�t know. Can anyone post a demonstration that FBC doesn�t fail FBC, or an example in which wv fails FBC?

Of course, if it takes a fair amount of work finding a wv FBC failure example, then, for all practical purposes, it�s really as if wv passed FBC, even if it doesn�t.

Likewise PC and GSFC & SDSC. PC passes SFC & WDSC, but hasn�t been shown to pass or fail GSFC or SDSC.

The fact that these things haven�t been demonstated is very different from saying that there�s a situation in FBC or GSFC doesn�t give a clear answer about whether a method passes. What I�m saying is only that, in every situation tested so far, PC passes GSFC, and in every situation tested so far, all the wv methods pass FBC.

Some criterion compliance/noncompliance determinations are just difficult. That doesn�t mean there�s something wrong with the criteria. It would be unreasonable to expect all methods to conveniently and easily show a failure example, or be shown to not have a failure example. Expecially, if there isn�t a failure example, showing that there isn�t one could be quite difficult, even if possible, for some methods. And not just for my criteria.

Mike Ossipoff

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