Every scholar in the fields of human capital or income distribution is indebted to Jacob Mincer [14, 15] for his pioneering work in integrating these two branches of economic theory. His contributions have been so forceful and original that there is now a danger that he may have succeeded too well, that the lessons he has taught us are hardening into dogma. In particular Rosenzweig and Morgan [17] seem to accept without question a specific functional form developed by Mincer wherein the logarithm of earnings is a linear function of years of schooling (S) and a quadratic function of a variable j defined as: