[EM] Margins examples

Michael Ossipoff mikeo2106 at msn.com
Sat Feb 24 01:36:52 PST 2007


I'll start with order-reversal, because that's what Juho's example was 
about:

Order-Reversal:

In the example below, the A voters prefer B to C, but are using offensive 
order-reversal in order to take victory from B. The B voters could be 
regarded as not having a preference among A and C, or considering A to not 
deserve a vote, or they could be defensively truncating (but with margins it 
won't work, and they need more drastic misrepresentation of their 
preferences in order to save B):

101: AC
100  B
50: CB

The B & C majority prevent A from winning by merely not ranking A. This is 
an SDSC example. And it's a margins SDSC failure example.

Truncation:

Either the A voters prefer B to C, but are employing offensive truncation 
(successfully in margins), or they don't have a preference among B and C, or 
maybe they're just being lazy, or are in a hurry. If they prefer B to C, 
then B is the CW, just as in the previous example:

101: A
50: BA
100: CB

Again, A wins in margins. The offensive truncation succeeds. Or, maybe lazy 
or hurried truncation took victory from B. Truncation doesn't affect wv in 
this way. With no one falsifying a preference, the B & C majority can keep A 
from winning merely by voting sincerely. This is an SFC example. And it's a 
margins SFC failure example.

Mike Ossipoff





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