The concept of NAIRU no longer makes sense

The equilibrium unemployment rate is most often defined as the NAIRU (non-accelerating inflation rate of unemployment), the unemployment rate that corresponds to the stability of inflation. But core inflation has been more or less stable in the euro zone since 2012 and in the United States since 2008; in the euro zone the unemployment rate, which has fallen from 12.2% in 2013 to 7.5% currently should always have been equal to the NAIRU in this period, which makes no sense. The same holds for the unemployment rate in the United States, which has fallen from 9.8% in 2009 to 3.5% currently. The reason is that if inflation is stable, the unemployment rate is by definition equal to the NAIRU. In reality, the disappearance of the link between economic cycle, labour cost growth and inflation, and the resulting stability of core inflation, have eliminated the concept of NAIRU, a (structural) equilibrium unemployment rate.