Interest rates are unlikely to follow a "smooth path" when the Federal Reserve begins tightening monetary policy, as the economy will "inevitably" encounter other shocks along the way, Fed vice-chair Stanley Fischer said yesterday.

The debate about whether to start hiking sooner and more slowly, or later and more rapidly, is still running on the Federal Open Market Committee (FOMC).

Last week Fed officials indicated a more gradual path was likely, compared with their earlier forecasts in