Monetary Policy Rules for an Open Economy

Abstract

The most popular simple rule for the interest rate, due to Taylor, is meant to inform monetary policy in closed economies. On the other hand, its main open-economy alternative, Ball's rule based on a monetary conditions index (MCI), may perform poorly in the face of specific types of exchange rate shocks, and thus cannot offer guidance for the day-to-day conduct of monetary policy. In this paper, a comprehensive set of simple monetary policy rules (including the MCI-based and Taylor versions) is specified and evaluated, all suitable for small open economies in general, and for the United Kingdom in particular. The asymptotic properties of a two-sector open-economy dynamic stochastic general equilibrium model calibrated on UK data are compared under the different rules. It is found that an inflation-forecast-based rule (IFB), i.e., one that reacts to deviations of expected inflation from target, performs well. Adding a separate response to the level of the real exchange rate (contemporaneous and lagged) appears to reduce the difference in adjustment between output gaps in the two sectors of the economy, but the improvement is only marginal. Importantly, an IFB rule, with or without exchange rate adjustment, appears robust to different shocks, in contrast to naive or Ball's MCI-based rules.