The euro zone is like this little boy who is looking under the street lamp the room that he has lost. "Are you sure you lost it here?" asked the old gentleman. "No," answered the child, but there is only here where one sees clear."

The great advantage of monetary policy is to be visible. Better, this is the one area where the european countries today have a common instrument, the european central Bank. The ECB operates in a manner that federal, like the Fed american, while the eurozone is not a federation. In particular, there is still no european budget worthy of the name, or even of genuine coordination of national budgetary policies. How to understand that Germany has this year a surplus in its public finances by 0.7 % of GDP, when France posted a deficit of 3.1 %? Why Berlin recorded an external surplus of 6 % to 7 % of its GDP, while Paris is in the red to the tune of 1 % to 2 %?

These disparities - one could ...