Optimal Monetary Policy and Exchange Rate Volatility in a Small Open Economy

We lay out a tractable small open economy version of the canonical sticky price model, and use it as a framework to study the properties of three alternative monetary regimes: (a) optimal monetary policy, (b) a Taylor rule, and (c) an exchange rate peg. Several interesting results emerge from our analysis. First, the optimal policy is shown to entail a positive correlation between domestic and world interest rates. That doesn't prevent sizable fluctuations of nominal and real exchange rates from occurring, though the implied volatility of those variables is much smaller than the empirical one. Second, a Taylor rule generally leads to excess volatility of nominal variables, and excess smoothness of real variables, relative to the optimal policy. Finally, we show that a pure exchange rate peg causes the equilibrium to be indeterminate and may thus be a source of macroeconomic instability.