The Fed embarked on the controversial purchase program because it could not lower interest rates any further from the already near-zero rates. Instead, it would buy back long-term Treasury bonds in monthly chunks, completing the $600 billion program at the end of July.
However, the move has set off a flurry of criticisms, primarily from Republican politicians, who argue QE2 monetizes the debt and will lead to high inflation.
The economists surveyed think rates will stay at that low level until unemployment shrinks to 8.6 percent from the current 9.8 percent level.
The survey matches the findings of a Dec. 23 economist poll conducted by CNNMoney.com. There, 22 of the 25 economists surveyed believed the Fed would buy all $600 billion of bonds as envisioned, and only one predicted there would be additional purchases afterward.