Earnings functions: Testing for the demand side

To analyze labor market phenomena, one may simultaneously grade workers (by education) and jobs (by level of difficulty and complexity). Human capital theory predicts earnings based on only worker quality. Thurow's version of a segmented labor market theory predicts that only the job level is relevant, and the assignment theory predicts that both variables are relevant. Using three different data sets for The Netherlands, testing demonstrates convincingly the superiority of the assignment theory.