----------------- HES POSTING ----------------- Help with references for the following ASK THE PROFESSOR inquiry would be appreciated. -- RBE When and with whom did the idea that earned incomes follow concave paths originate? Also, when and who first described the traditional human capital accumulation pattern, i.e. that schooling occurrs at a relatively young age followed by on the job training? Regarding the latter question, B.F. Kiker in \"Human Capital: In Retrospect\" 1968 reveals that Ernst Engals described this pattern in the 1880s. Any specific references would be appreciated. ------------ FOOTER TO HES POSTING ------------ For information, send the message "info HES" to [log in to unmask]