““Marx makes several assertions about this particular sort of value producing labor that are often ignored, even altogether dismissed, by most of the people who write popular introductions to Capital. First, we cannot see it directly, but only in the form of the exchange ratio one commodity has with another. Second, this labor is not the labor of any individual, but only of the community of producers as a whole. Third, this particular value producing labor is strictly limited in its duration to the socially necessary labor time required for production of commodities. Fourth, the duration of this value producing labor diminishes as the development of the productivity of the labor increases. Fifth, labor cannot produce value unless it also produces a socially useful object that is exchange for another commodity in the market.””
