In To Prevent Bubbles, Restrain the Fed, Cato's Gerald P. O'Driscoll Jr. writes, in an article otherwise opposed to policies that cause "the boom and bust cycle":

"At first Fed easing was in order. The central bank needed to counter the "irrational exuberance" of the dot-com bubble. And by May of 2000 the Fed had done that by raising the fed-funds target to 6.5%. That needed to come down when the bubble burst. Aggressive cutting brought it to 2% in November 2001. The problem is the rate remained at 2% or less for three years (for a year it was at 1%)."

So, it's okay to have artificially low interest rates when it's "needed"--but not for too long! Ah, there's the rub--finding just the right length of time to "ease"... we'll get it right someday, I'm sure.