The goal of the Federal Reserve's low interest rate policy is to juice the economic recovery. The low rates should make it easier for people to borrow money, which they'll hopefully spend; the increased demand for goods and services is then supposed to translate into more hiring.
That's what the Fed is banking on. It hopes low interest rates will help with its mandate of achieving maximum employment, but it also has another mandate: to keep prices stable.
"In many cases, those two conflict," says economist Joe Gagnon of the Peterson Institute for International Economics.