WASHINGTON -- No sooner did the Federal Reserve unveil a bold plan Thursday to juice the U.S. economy than it dangled the prospect of doing even more.
Investors celebrated by sending stock prices jumping.
Economists were less impressed. Many wondered how much the Fed's action would help.
Chairman Ben Bernanke himself urged everyone to keep expectations in check.
"I personally don't think that it's going to solve the problem," Bernanke said at a news conference. "But I do think it has enough force to help nudge the economy in the right direction."
The Fed's move to buy $40 billion a month in mortgage bonds -- the heart of its plan -- might do little to spur borrowing and spending because rates on mortgages and other loans are already just above record lows.
The bond purchases, and the Fed's signal that more help might be needed, pointed to just how weak the U.S. economy remains three years after the recession ended. The economy is still struggling to emerge from damage caused by the 2008 financial crisis -- the worst since the Great Depression.
The Fed's plan raises questions about the limits of its own power. Even with its intervention, the Fed foresees unemployment remaining as high as a recession-level 6.8 percent as late as 2015.
In the face of persistently high unemployment and slow economic growth, the Fed said Thursday that it would:
- Buy $40 billion a month in mortgage bonds indefinitely to try to lower long-term interest rates, encourage home buying and get people to borrow and spend more. It's the Fed's third bond-buying program. If job growth doesn't improve much, the Fed will continue its bond purchases and take other steps.
- Likely keep its benchmark short-term rate at a record low near zero through at least mid-2015. That's six months longer than the Fed had previously planned.
- Probably hold interest rates low even well after the economic recovery has strengthened.
The mortgage bond purchases are unlikely to boost home sales much, even if they manage to lower mortgage rates further. The average rate on a 30-year fixed mortgage is already 3.55 percent, barely above the record low of 3.49 percent.
Home sales remain depressed in part because would-be buyers can't qualify for loans unless they have stellar credit or can produce hefty down payments.
"If you get a 2 percent mortgage but you've got to put 30 or 40 percent down, is that going to encourage people to buy a house?" said Doug Roberts, chief investment strategist at Channel Capital Research.
Still, Bernanke maintained that the Fed can help further, even with rates already ultra-low. He's argued that the Fed's first two rounds of bond purchases, in which it bought more than $2 trillion in bonds, saved 2 million jobs and accelerated growth.