Trends in the payoff to academic and occupation-specific skills: the short and medium run returns to academic and vocational high school courses for non-college-bound students

Using data from three longitudinal surveys of American high school students, I show that vocational courses helped non-college-bound students to start their work life more successfully. A comparison of the returns to academic and vocational course work for non-college-bound students who graduated in 1972, 1980 and 1992 finds that the short and medium term payoffs to vocational courses rose substantially between 1972 and 1980 and remained high in 1992. Holding a host of variables constant, academic course work had much smaller labour market payoffs than vocational course work. These findings contradict the often repeated claim that employers now seek workers with a good general education and are happy to teach the occupation specific skills necessary to do the job. High school students who do not plan to attend college full-time would be well advised to start studying a well paying occupation before they complete high school. [JEL: I20, J23, J24]     

CONNECTIONISM AND THE EMERGENCE OF KNOWLEDGE

Procedures for creating used by connectionist networks with hidden units are analyzed. With these networks it is possible to create by modification of the inputs, by modification of collector properties, by modification of connections between units and variation of thresholds of activation, by modification of constraints imposed on the network, by creation of new hidden units or by creation of new outputs. The interest of connectionist networks is in simulating various processes to allow analysis of modifications that are efficient and capable of concretizing the consequences of choices. Networks must be designed as tools capable of helping formalize problems, and not as replicas of cognitive processes.