Last week, the central Banks of the United States, the United Kingdom and the euro zone had each one a meeting in a context affected by the uncertainties about the evolution of the covid-19 pandemic, about the durability of the economic rebound in the concerned countries and about the character of the inflation which affects them in order to define and to make public the guidelines of their monetary policy for the year to come. Through the definition of a guideline, these institutions which have become essential actors of the economic policy intend to avoid the disorders which could occur ...