This paper provides a method for linearly combining skill classes so that the number of classes required to describe a skill distribution is minimized. The principal analytical device is that of distinguishing between skill classes and the characteristics of persons in a class. The distinction...

This represents two chapters of a proposed book co-authored by Bob Evenson and myself. The subject is relationships between agricultural productivity, research and information. The first chapter of this part is concerned with the "theory" of the value of information. Among other things, the...

The "human capital earnings function," in which earnings are expressed as a quadratic in potential experience, is probably the most widely accepted empirical specification in economics. In spite of its widespread acceptance, the human capital earnings function provides a very poor approximation...