The Fed's capabilities to engineer changes in economic growth and inflation are asymmetric. It has been historically documented that central bank tools are well suited to fight excess demand and rampant inflation; the Fed showed great resolve in containing the fast price increases in the aftermath of World Wars I and II and the Korean War. In the late 1970s and early 1980s, rampant inflation was again brought under control by a determined and persistent Federal Reserve.
However, when an economy is excessively over-indebted and disinflationary factors force central banks to cut overnight interest rates to as close to zero as possible, central bank policy is powerless to further move inflation or growth metrics. The periods between 1927 and 1939 in the U.S. (and elsewhere), and from 1989 to the present in Japan, are clear examples of the impotence of central bank policy actions during periods of over-indebtedness.