Similarly, the ECB also has to assess the quantitative significance of spillback mechanisms in setting monetary policy, which is the subject of ongoing research by ECB staff. [37]  Of course, the strength of these spillover-spillback loops also depends on the monetary policy reaction functions in emerging economies: the interdependencies in monetary policy run in both directions.
In particular, as I emphasized in a speech last spring, the Federal Reserve can determine and achieve the long-run average rate of inflation in keeping with its dual mandate, but the Federal Reserve most emphatically cannot choose the level of maximum sustainable economic activity--no central bank can control the level of real economic activity or employment over the longer run (Mishkin, 2007a).