As the Federal Reserve prepares to raise interest rates for thefirst time since 2006, almost all the talk of a potential policymisstep has centered on the peril of hiking too soon.

The bigger concern is that the Fed may wait too long, say ThomasLam at RHB Securities Singapore Pte. Ltd and David Glocke atVanguard Group Inc. A decision to keep the overnight rate near zeroon Sept. 17 may wind up jolting debt markets more than actuallyraising it, said Lam, who according to Bloomberg was thefourth-most-accurate forecaster of the U.S. economy lastquarter.

The worry is that by holding its target at crisis-period levelstoo long, the Fed may fail to get ahead of a strengthening economy.That would push up yields as traders anticipate that policy makerswill have to adopt a more aggressive approach to lifting interestrates than the gradual path Fed Chairman Janet Yellen hasstressed.