I'm hoping some game theorists will chime in here; it doesn't matter if you don't get macro. I need your help, and want your thoughts on my intuitions:
Not all Nash equilibria are created equal.
Game A. There are n identical players who move simultaneously. Player i chooses Si to minimise a loss function Li = (Si-Sbar)2 + (Si-Sbar)(Sbar-S*), where Sbar is defined as the mean Si over all players, and S* is a parameter that is common knowledge to all players.
This game has a unique Nash equilibrium Si = Sbar = S*.
Game B is exactly the same as game A, except the loss function is now Li = (Si-Sbar)2 + (Si-Sbar)(S*-Sbar). (I flipped the sign of the last bracketed term.)
This game also has a unique Nash equilibrium Si = Sbar = S*.
I think the Nash equilibrium in game A is plausible, but the Nash equilibrium in game B is implausible.