Uncertainty and the choice of instruments in a two-country monetary-policy game

In the two-country, monetary-policy game of this paper, each policymaker can choose his money supply or his interest rate as his instrument. With no uncertainty there are four noncooperative equilibria, one for each possible instrument pair. A policymaker is indifferent between instruments: his payoff depends not on his choice but on his opponent's. With uncertainty, the number of equilibria is reduced, sometimes to one. A policymaker is not indifferent between instruments; his payoff depends on his choice as well as on his opponent's. In some cases each policymaker prefers the equilibrium instrument choice of his opponent, but in others at least one would prefer another choice.