Federal Reserve Chairman Ben S. Bernanke tomorrow may disappointstock investors betting on a commitment to step up stimulus. He haslittle choice, given rising consumer prices and a U.S. economy thatis still growing.

Gasoline costs are 33 percent higher, consumer inflation istwice as fast and inflation expectations are above levels sinceBernanke signaled more easing a year ago at the annual Fedsymposium in Jackson Hole, Wyoming. While the U.S. expansion hasslowed, the Chicago Fed's index of 85 economic indicators improvedin July for a third month on gains in production.

Policy makers, who said Aug. 9 they'll use additional tools “asappropriate,” probably don't expect a recession or rapiddisinflation, making a signal of bond buying premature, saidRoberto Perli, managing director at International Strategy &Investment Group in Washington. Instead, Bernanke will probablydetail options for further stimulus and clarify how much the Fed'sreduction in its outlook this month stems from long-term obstaclesto growth, said Keith Hembre, a former Fed researcher.