I want to admit that I don't know whether or not Smith//PC fails GSFC & SDSC. Since no one's proposing Smith//PC, it doesn't seem important. But, aside from Tideman's other advantages, described by Steve & Blake, Tideman(wv) & SSD have the big advantage over Smith//PC that they've been shown to meet GSFC & SDSC. I don't want to discourage Markus, or anyone, from proposing Smith//PC if they like it. I can't guarantee its GSFC & SDSC compliance though. I haven't yet succeeded in finding a GSFC failure example for Smith//PC. Maybe it fails, maybe not. Maybe someone can show one way or the other. Anyway, it seems more relevant to show that IRV fails GSFC & SDSC. In fact, as I said, IRV fails SFC & WDSC, and that means that IRV fails GSFC & SDSC. I write, here, IRV failure examples for SFC & WDSC. In addition to showing that IRV fails those criteria, it serves to demonstrate the use of those 2 criteria: GSFC: 100 voters. 3 candidates. The criterion says that a candidate (whom I'll call "A") is SCW, and that a majority vote him over B. That means that the criteria specifies something about sincere preferences & something about votes. My example complies with what the criterion specifies, and an example-writer can configure everything else as he wants to. Sincere prefernces: 40: BAC 25: ABC 35: CAB Votes: Voters vote exactly in accordance with their sincere rankings. So: A is SCW, based on the sincere rankings. A majority vote A over B. No one is falsifying a preference. The premise of the criterion is met. Now, what happens? A gets eliminated, transfers to B, and B wins. The criterion says that B must not win. IRV fails SFC, and therefore IRV fails GSFC too. WDSC: 100 voters. 3 candidates. All the criterion specifies is that a majority of all the voters prefer A to B. My example complies with that, and anything else not specified can be configured as I choose. Sincere preference of 60 voters: 25: ABC 35: CAB That's a majority who prefer A to B. I'll call them "the A>B majority". Other people's votes: 40: BAC (That's the actual voted ranking of the other 40 voters). The criterion says that the A>B majority must have a way of making B lose without any member of that majority reversing a preference. How can they? For A to transfer to C instead of the B, his voters would have to vote C 2nd--reversing the preference for B over C. (Of course the A voters have no motivation to do that, but that's beside the point). The C voters could keep B from winning by insincerely voting A in 1st place, over C. (That's what they'll feel forced to do in actual practice). That means they're reversing their CA preference. There's no way the A>B majority can make B lose without reversing a preference. IRV fails WDSC, and therefore IRV fails SDSC. 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 http://profiles.msn.com.
