The problem is that if you try to maintain no inflation, you run the risk of succeeding too well and getting deflation. Deflation is known to lead to persistent recessions, and is very, very difficult to fix once it sets in. (Just ask Japan how deflation has been for them. Or the USA how we liked the Great Depression.)
Therefore it isn't as simple as inflation bad, no inflation good. Rather it is too much inflation bad, any deflation bad, and you need to be in the middle. Which means that you want to maintain a small amount of persistent inflation - just enough to avoid the risk of miscalculating and going into deflation, but no more.
A big worry for the USA at the moment is that the current credit issues could lead to deflation.
Therefore it isn't as simple as inflation bad, no inflation good. Rather it is too much inflation bad, any deflation bad, and you need to be in the middle. Which means that you want to maintain a small amount of persistent inflation - just enough to avoid the risk of miscalculating and going into deflation, but no more.
A big worry for the USA at the moment is that the current credit issues could lead to deflation.