Into the Mussa puzzle: monetary policy regimes and the real exchange rate in a small open economy

Industrial countries moving from fixed to floating exchange rate regimes experience dramatic rises in the variability of the real exchange rate. This evidence, forcefully documented by Mussa [Nominal exchange regimes and the behavior of real exchange rates: evidence and implications. Carnegie-Rochester Conference Series on Public Policy 25 (1986) 117], is a puzzle because it is hard to reconcile with the assumption of flexible prices. This paper lays out a dynamic general equilibrium model of a small open economy that combines nominal price rigidity with a systematic behavior of monetary policy able to approximate a continuum of exchange rate regimes. A version of the model with complete exchange rate pass-through is broadly consistent with Mussa’s findings. Most importantly, this holds independently of the underlying source of fluctuations in the economy, stressing the role of the nominal exchange rate regime per se in affecting the variability of the real exchange rate. However, only a model featuring incomplete exchange rate pass-through can account for a broader range of exchange rate statistics. Finally there exist ranges of values for either the degree of openness or the elasticity of substitution between domestic and foreign goods for which the baseline model is also consistent with the empirical insensitivity of output volatility to the type of exchange rate regime, as documented by Baxter and Stockman [Journal of Monetary Economics 23 (1989) 377].