We study the relationship between equilibrium existence and uniqueness in LQ-games, and the classical theory of economic policy. By focusing on system controllability, we find necessary conditions for the existence and uniqueness of the Nash equilibrium that generalize results in the existing...

By introducing the concepts of implicit coalitions and conflict of interests in a multiple-player context, this paper generalizes some theorems on policy invariance and equilibrium existence and uniqueness for LQ policy games.