What kind of idiot economist is he?
As far back in history as you care to look, surplus of labor leads to economic stagnation and shortage of labor leads to economic growth. A shortage of labor means better wages for more people, and spurs technological innovation that increases productivity.
A surplus of labor, on the other hand, increases the relative value of capital and directs more wealth to fewer people who have no incentive to innovate.
He appears to be of the John Kenneth Galbraith variety.