[EM] UncAAO

[Michael Ossipoff]

Forest had correctly said:

Under winning votes the C faction can take defensive action and
truncate to 20 C.  The resulting position is a Nash Equilibrium.

Chris writes:

Taking such "defensive action" causes B to win, so why would they want to do 
that when they
prefer A to B? And I don't see why the resulting position is a "Nash 
Equilibrium"
(according to
the definition I googled up), because the sincere C>A faction can change the 
winner from B to A
by changing their votes from C to C>A.


I reply:

The Nash equilibrium isn’t one in which the offensive order-reversal takes 
place. In the Nash equilibrium, the C voters truncate, and the would-be 
order-reversers don’t order-reverse. The B voters wouldn’t benefit by 
changing their vote, and the would-be order-reversers would suffer if they 
order-reversed. That’s the Nash equilibrium. The B voters, by truncating, 
make the would-be reversers accept the Nash equilibrium or suffer the 
consequences.

Mike Ossipoff



DEFINITION: Nash Equilibrium If there is a set of strategies with the 
property that no player
can benefit by changing her strategy while the other players keep their 
strategies unchanged, then
that set of strategies and the corresponding payoffs constitute the Nash 
Equilibrium.
http://william-king.www.drexel.edu/top/eco/game/nash.html