[EM] In the example, IRV fails SFC too.

MIKE OSSIPOFF nkklrp at hotmail.com
Fri Nov 17 01:02:21 PST 2000

In Blake's example, A is the sincere CW, and so, if we assume that
no one is falsifying their preferences, IRV is failing SFC in
that example. A majority vote the SCW over B, and B wins.

Of course the sincere CW is a 1-candidate Smith set, and so the
example is automatically a GSFC failure too.

The FBC2 criterion that I wrote in my recent message isn't one that
I'll use a lot. There are other, maybe better, ways it could be written,
too. But let me just say what can be said about IRV in that regard:

Whenever all that's known about the election is that a certain set
of candidates are a mutual majority set, with some particular majority-
size group of voters prefering them all to everyone outside that set,
then for anyone whose favorite is outside that set, his only
undominated strategies will involve voting someone over his favorite.

That's why I say that every MMC example is a badexample for IRV.
In the case of Blake's example, as is probably common in that instance,
IRV actually fails the defensive strategy criteria, all of them.
But, even in general it what I said in the previous paragraph will hold.

Mike Ossipoff

Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

Share information about yourself, create your own public profile at 

More information about the Election-Methods mailing list