I find this article today. In short, it is complicated.
In my opinion, it is almost insufficient to only consider what the QE3 has brought us without considering the alternative of doing nothing. It is easy, in hindsight, to criticise the Federal Reserve’s QE3 program, but can we really imagine what the world (or the US) would be like without it?
Economists generally love to find a real world example to learn from. In that spirit, I would suggest looking at Europe and Japan. Both, initially, did not embrace aggressive credit stimulus program. Europe is under constant threat of deflation. Japan has been in deflation for a decade. Both central banks are now engaging in programs similar to the QE programs.
Having said this, I am not trying to simplify the difficulty in understanding the usefulness of QE3. Problems for European and Japanese economies are subtle than I have suggested. I simply wish to allude to their money supply problems.
I will write more on the QE programs later.