NEW YORK (CNN/Money) - A closely watched measure of U.S. consumer confidence came in a bit worse in September than initially thought, according to published reports Friday, though it's uncertain the report says much about the future of consumer spending, a pillar of the broader economy.

The University of Michigan's consumer sentiment index was revised downward to 86.1 in September from an initial reading of 86.2 and August's reading of 87.6, according to a Reuters report. Economists, on average, expected a revised reading of 86, according to Briefing.com. The report is available only to paying subscribers.

While the Michigan sentiment numbers and another closely watched confidence measure from the Conference Board, a private research firm, have fallen steadily this summer, consumers have kept on spending.

"If spending numbers looked like sentiment numbers, we'd be back in recession," said Robert Barbera, chief economist at Hoenig & Co. Inc. "The good news is that consumers are complaining, but they're spending."

The report had little impact on U.S. stock prices, which fell in early trading. Treasury bond prices rose.

The university's current conditions index, which measures how consumers feel about the economy at present, fell to a revised 95.8 from 98.5 in August. The expectations index, measuring how consumers feel about the future, fell to a revised 79.9 from 80.6.

Consumer spending is closely watched since it fuels about two-thirds of the world's largest economy. Robust spending helped carry the economy through a recession that began in March 2001, the Sept. 11 terrorist attacks and other shocks.

The Federal Reserve helped to keep consumers spending by cutting its target for short-term interest rates 11 times in 2001, lowering the cost of borrowing.

The Fed decided this week to leave rates alone, as it has done all year, because policy makers were uncertain about the economy's strength.

Future consumer spending will likely hinge on what businesses do. An abrupt decline in business investment in 2000, followed by more than 1.5 million job cuts in 2001, helped fuel the recession.

Unemployment has hovered at about the same rate all year, while new jobs have been scarce, raising comparisons with the "jobless" recovery that followed the 1990-91 recession. With stock prices falling and America preparing to go to war with Iraq, threatening higher energy prices, that's a powerful cocktail to discourage spending.

But consumers have weathered all this, in part, because mortgage rates have plunged, setting new lows almost every week, enabling homeowners to refinance their mortgages to get lower monthly payments and to borrow against their home equity, which has grown as home prices have risen.

"Right now, we have a tug-of-war between the negative consequences of a jobless recovery and the powerful cash-flow effects of a once-in-a-generation mortgage refinancing boom," Barbera said.