Euro Area Inflation Differentials: Unit Roots, Structural Breaks and Non-Linear Adjustment

This paper examines the time series properties of inflation differentials in twelve EMU countries. We compute three alternative measures of inflation differentials using deviations from the policy reference value implied by the Maastricht Treaty, the ECB target, and deviations from the EMU average inflation. The evidence from standard linear unit root tests indicate that inflation differentials are highly persistent. However, when we account for endogenously determined structural breaks, we obtain greater support for stationarity. In addition, when we allow for the possibility that inflation differentials can be charterised by a non-linear mean reverting process we find evidence of stationarity. Our empirical results suggest that once we allow for structural breaks or non-linearities, inflation differentials do not consistently intensify real divergence in the euro area