Outgoing Federal Reserve chair Ben Bernanke yesterday offered a candid appraisal of the unorthodox monetary policy measures launched under his watch, conceding that the Federal Open Market Committee (FOMC) had at times bungled its communication efforts, but defended its policies as necessary to avoid Japan-style deflation.

Speaking at an event in Washington DC, Bernanke said the sharp rise in US Treasury yields in the wake of comments he made about the Fed's monthly asset purchasing programme in