The tragedy of the commons and inflation bias in the euro area

Central bank credit has expanded dramatically since the beginning of 2007 in some of the euro area member countries. This paper makes two contributions to understand this stylized fact. First, we discuss a simple model of monetary policy that includes (i) a credit channel and (ii) a common pool problem in a monetary union. We illustrate that the interaction of the two elements leads to an inflation bias that is independent of the standard time-inconsistency bias. Secondly, we present empirical evidence that is consistent with the view that national central banks in the euro area have indeed followed an independent monetary policy. We find that inflation was the main determinant of central bank credit prior to 2007. After 2007, it closely follows unemployment in the respective countries.