Policy instrument choice and non-coordinated monetary policy in interdependent economies

Non-coordinated monetary policy is analyzed in a stochastic two-country general equilibrium model. Non-coordinated equilibria are compared in two cases: one where policy is set in terms of state-contingent money supply rules, and one where policy is set in terms of state-contingent nominal interest rate rules. In general, the non-coordinated equilibrium differs between the two types of policy rule, but a number of special cases are identified where the equilibria are identical. The endogenous choice of policy instrument is analyzed and the Nash equilibrium in the choice of policy instrument is shown to depend on the interest elasticity of money demand.