Monetary policies have such effects on fiscal policies that it is no longer possible to maintain central bank independence

Central bank independence means in particular that there is no coordination of fiscal and monetary policies. The absence of coordination does not lead to a loss of well-being only if there is no externality of fiscal (governments) policies on monetary policies (on central banks) or of monetary policies (central banks) on fiscal (government) policies. This is the case in the simple model often used where, in the long term , monetary policy determines inflation and has no impact on the real economy, and where the central bank only has an inflation target. But nowadays, the highly expansionary monetary policies have a major impact on many fiscal policies, by allowing fiscal deficits and public debt to be higher (in the United States, France, Italy and Japan). There is therefore an externality of monetary (the central bank's) policy on fiscal (the government ’ s) policy that should impose a coordination of the two policies. Currently, the countries that accept a high public debt ratio assume that interest rates will remain low for a long time. It would be better for this assumption to be coordinated between governments and central banks rather than made unilaterally by governments with respect to independent central banks.