Monetary Policy in a Dual Currency Environment

We develop a small open economy general equilibrium model with sticky prices and partial dollarization - a situation where both domestic and foreign currencies coexist. We derive a tractable representation of the model in terms of domestic in‡flation and the output gap in which a trade-off, which depends on the degree of dollarization, arises endogenously due to the presence of foreign interest rate shocks. We use this framework to show analytically how higher degrees of dollarization induce larger volatilities of the output gap and in‡flation, thus hampering a central bank's effectiveness in stabilizing the economy. Our impulse-response functions show that the transmission of such shocks has a positive (negative) effect on in‡flation and negative (positive) effect on the output gap when money aggregates and consumption are complements (substitutes). We also show that a standard Taylor rule guarantees real determinacy of the rational expectations equilibrium. Finally, we demonstrate that a higher degree of dollarization reduces the determinacy region when the overall money aggregate and consumption are substitutes.