I never understood the fuss about the transformation problem. How do you know whether labor is socially necessary labor until after values have been realized in the market? Until after commodities actually become exchange values? Labor producing unsold widgets is not socially necessary labor, but we don't know that until we close the circle and see production and circulation of capital as a contradictory unity. Production is "more important" in that you have to produce something (gifts of nature excepted) before it can be exchanged or distributed, i.e., is logically prior to exchange. Until the market clears (or not), we don't know whether or not this or that labor is socially necessary. I'm repeating myself. Jim O'Connor