Washington, Nov 05: Federal Reserve chairman Alan Greenspan is set to break a long silence about the US economy on Thursday with a speech on “economic developments” to a securities industry audience, the Fed said on Monday. Greenspan’s last extensive remarks on the economy came in mid-July. Since then, the recovery has gained speed, although hiring has yet to pick up appreciably. The economy roared ahead at its fastest pace in nearly two decades in the third quarter, galvanised by tax cuts. Bureau Report