ROBERT SIEGEL, HOST:
Now, a look back at efforts this year to boost economic growth. The Federal Reserve kept its foot on the accelerator using some unusual tactics. And as NPR's John Ydstie reports, economists disagree about whether the Fed's policies were effective or whether the risks outweigh the rewards.
JOHN YDSTIE, BYLINE: Chairman Bernanke and the Federal Reserve employed two main tools in 2012 to try to boost economic growth: first, Operation Twist in which the Fed bought long-term Treasury bonds; second, a program to purchase mortgage-backed securities. Both were aimed at driving down long-term interest rates. One goal was to boost the housing market. Mark Zandi of Moody's Analytics says the Fed's effort has been a big plus.
MARK ZANDI: It's lowered mortgage rates, which has helped lots of homeowners refinance their mortgages and lower their monthly payments. It's certainly been key to turning the housing market around, and housing is vital to the strength of the broader economy. It's helped to lift stock prices, and stocks are very important to collective thinking and people's perceptions about how well we're doing.
YDSTIE: And, Zandi says, the Fed's efforts have kept the value of the dollar low, which has helped U.S. exports. Nariman Behravesh, chief economist for the research firm IHS Global Insight, also thinks the Fed's policies provided an important boost for the economy in 2012.
NARIMAN BEHRAVESH: You know people say, oh, you know, it's done more harm than good. I think that's nonsense. It has had a small, but nevertheless positive impact in particular on housing.
YDSTIE: One economist who thinks the Fed's policies in 2012 - and for the past few years - have created risks for the economy is Harvard professor Martin Feldstein.
MARTIN FELDSTEIN: Risk in the sense that they could produce inflation in the future and that there's also a serious risk that they're creating asset price bubbles that, like all bubbles when they burst, could be vey damaging.
YDSTIE: Feldstein believes the Fed's success in pushing down long-term interest rates is inflating the value of assets like homes and stocks and bonds. And when the Fed has to reverse course as the economy picks up, the prices of those assets will take a tumble and damage the economy.
FELDSTEIN: It feels good now while it's happening, but I think it lays a trap for us later on.
YDSTIE: Peter Fisher, a former Treasury official who's now senior managing director at the Wall Street firm BlackRock, says the Fed's policy of pushing long-term interest rates to extremely low levels comes with tradeoffs.
PETER FISHER: On the one hand, you can be holding down the cost of refinancing a mortgage and hope to encourage people to borrow. On the other hand, by holding down the long end, you're discouraging lenders.
YDSTIE: That's because when rates get extremely low, the profit margins that lenders can make on loans shrink, so banks make fewer loans and credit gets tight. Despite his concerns, Fisher generally supports the Fed's actions, except for Operation Twist. Moody's Mark Zandi argues the economy would be significantly worse off if the Fed had demurred.
ZANDI: If the Fed had not engaged in these extraordinary actions, the economy would feel a lot worse. You know, we'd have an unemployment rate closer to 9 percent as opposed 8 percent. That's a palpable difference.
YDSTIE: Harvard's Martin Feldstein says it will likely be a couple of years before we see the negative effects of inflation and asset bubbles. But clearly, Ben Bernanke and most of the Fed's governors think the rewards of the policy outweigh the risks. They've made it clear they'll likely hold rates low throughout 2013. John Ydstie, NPR News, Washington.