INFLATION PERSISTENCE AND UNIT ROOT TESTS IN THE EURO AREA COUNTRIES

Persistence is one of the main characteristics of inflation. One of the definitions of persistent inflation is, that it is the rate at which inflation reaches equilibrium after a certain macroeconomic shock. If the inflation persistence is high, the response to inflation shocks is longlasting and difficult for the central bank to control. Conversely, if the country’s inflation persistence is low, the central bank can keep the inflation rate in line with the inflation target. The recent economic crisis made central banks adopt several unconventional monetary policy instruments to boost economic recovery and preserve price stability. Many authors note that data on stationary inflation in the euro area countries is a precondition for joining the European Union. As far as the functioning of the European Union is concerned, it is desirable to take the necessary decisions. The primary objective of the paper is to test the inflation rate data in the euro area countries to verify the existence of a unit root considering that central banks design their monetary policy frameworks under the assumption that inflation is a stationary process. The verification of the stationarity of the inflation data is divided into two sections. In the first section, the monthly data panel of the Harmonised Index of Consumer Prices (HICP) for euro-zone countries is used. The second section uses a panel of monthly data the Harmonised Index of Consumer Prices for each category of Classification of Individual Consumption by Purpose for euro area countries. Our results indicate that time series for inflation in 11 of 19 euro area member countries are non-stationary and have a unit root. Considering our results we propose the creation of a two-speed euro area and the adjustment of the monetary policy framework in the euro area countries.