Tideman & GMC

[Mike Ositoff]

In my Tideman bad-example, I neglected to say how many voters
there are. Say there are 12 voters.

Then D's defeat by A is unanimous. B's defeat by D is with
an 83.3% majority. C isn't majority-defeated, only having 1
vote against it in a defeat.

So Tideman's method, at least as defined in the 
_Journal of Economic Perspectives_ article, as I interpret
the article, does violate GMC.

It also violates Beat-Path GMC:

In C's only defeat, C is only beaten with 1 vote against. That
means that there can be no beat-path to C that's stronger than
1. Now, say C beats A with 7 votes-against, instead of 5.
(Or with 11, for that matter). Now there's a majority beat-path
from C to B, but not from B to C. B is disqualified by
Beat-Path GMC. But Tideman electes B, which is disqualified
by both versions of GMC.
 

Mike Ossipoff