"American middle-class wealth has moved to upper-class rather than to outsiders."
As your quote says, it's not the wealth that has moved per say, but that people have moved upward out of the middle class and brought that wealth with them with more people moving up than moving down.
As your quote says, it's not the wealth that has moved per say, but that people have moved upward out of the middle class and brought that wealth with them with more people moving up than moving down.