[EM] UncAAO
Forest W Simmons
fsimmons at pcc.edu
Fri Mar 2 14:54:30 PST 2007
Here are the main advantages of UncAAO over other Condorcet methods:
1. It is resistant to manipulation ... more so than Beatpath or Ranked
Pairs, if I am not mistaken.
2. It always chooses from the uncovered set.
3. It is at least as easy as Ranked Pairs to describe. No mention of
the possibility of cycles is needed, since the covering relation is
transitive.
4. It is easier than Ranked Pairs or Beatpath to compute. One never
has to check for cycles, since the covering relation is transitive.
5. It takes into account strength of preference through appropriate
use of Approval information.
With regards to point 1, consider the following example (sincere votes):
45 A>C>B
35 B>C>A
20 C>A>B
This is not a Nash Equilibrium for Margins, Ranked Pairs, PC, etc.
because the A faction can improve its lot unilaterally by reversing C>B
to B>C.
Under winning votes the C faction can take defensive action and
truncate to 20 C. The resulting position is a Nash Equilibrium.
But under Unc, there is a Nash Equilibrium that involves no order
collapse:
45 A>>C>B
35 B>C>>A
20 C>>A>B
Forest
More information about the Election-Methods
mailing list