"The conventional view among economists is that education adds to an individual's productivity and therefore increases the market value of his labor. From the viewpoint of formal theory, it does not matter how the student's productivity is increased, but implicitly it is assumed that the student receives cognitive skills through his education. Educators, on the other hand, have long felt that the activity of education is a process of socialization, with the latent content of the process—the acquisition of skills such as the carrying out of assigned tasks, getting along with others, regularity, punctuality, and the like—being at least as important as the manifest objectives of conveying information. This last doctrine has been revived by radical economists, though with a negative rather than a positive valuation. But from the viewpoint of economic theory, the socialization hypothesis is just as much a human capital theory as the cognitive skill acquisition hypothesis. Both hypotheses imply that education supplies skills that lead to higher productivity. I would like to present a very different view. Higher education, in this model, contributes in no way to superior economic performance; it increases neither cognition nor socialization. Instead, higher education serves as a screening device in that it sorts out individuals of differing abilities, thereby conveying information to the purchasers of labor."