Capitalism Is Justified Because It Is an "Engine for Generating Creative Workplaces"
(p. 121) Phelps: . . . Since 2002, I've been trying to develop a new justification for capitalism, at least I think it's new, in which I say that if we're going to have any possibility of intellectual development we're going to have to have jobs offering stimulating and challenging opportunities for problem solving, discovery, exploration, and so on. And capitalism, like it or not, has so far been an extraordinary engine for generating creative workplaces in which that sort of personal growth and personal development is possible; perhaps not for everybody but for an appreciable number of people, so if you think that it's a human right to have that kind of a life, then you have on the face of it a justification for capitalism. There has to be something pretty powerful to overturn or override that.
For the full interview, from which the above is quoted, see:
Vane, Howard R., and Chris Mulhearn, interviewers. "Interview with Edmund S. Phelps." Journal of Economic Perspectives 23, no. 3 (Summer 2009): 109-24.
(Note: ellipsis added.)