The replacement of national currencies by a common currency in the EMU causes a monetary externality if the European Central Bank is inclined to monetize part of outstanding government debt in the community.High government debt in one part of the EU then increases the common inflation rate.We model debt stabilization in the EU as a differential game between fiscal authorities and the ECB.Three different equilibria are considered: the Nash open-loop equilibrium, the Stackelberg open-loop equilibrium with the ECB leading and the Stackelberg open-loop equilibrium with the fiscal authorities leading.Dynamics of the fiscal deficits, inflation and government debt in a monetary union are derived and compared with an EU with national monetary policies
