Thanks!
Two of those references link back to the Economic Policy Institute ("Research and Ideas For Working People), which pretty much says all you need to know about that.
The Forbes reference is from a place called Global Insight, which is a new one on me. Their U.S. economy page is here, and it looks like interesting reading. Several good articles just on this page, including this one and this one.
I did not find the specific paper referred to by Forbes, but sometimes these are paid studies, and don't show up in the public domain.