Schooling as Human Capital or a Signal: Some Evidence

A new way is proposed to distinguish between the human capital and the signaling theories of the value of education. If education is a signal, then the essence of the signal should be distilled in the position of an individual in the distribution of education for his cohort. Estimating earnings equations that include both absolute (years) and relative (percentile) measures of education provides a test of the two competing theories. Analyzing two separate panel data sources under a range of alternative specifications, we find that the years measure of schooling has a consistently significant positive effect on earnings, but that the rank measure rarely does. This evidence supports the conclusion that human capital rather than signaling is the predominant explanation of schooling's value.