The consensus view is that central banks under currency boards
do not have tools for active monetary policy. In this paper we
analyze the foreign exchange fee as a monetary policy instrument
that can be used by a central bank under a currency board. We
develop a general equilibrium model showing that changes in this fee
may have the same effects as a change in the monetary policy stance.
Thus, central banks operating under the currency board are shown to
have an avenue to implement active monetary policy.