Growth in within graduate wage inequality: The role of subjects, cognitive skill dispersion and occupational concentration

Increasing participation in Higher Education, and the rising number of graduates in the labour markets of most developed countries, are likely to alter graduate wage distributions. Increasing wage inequality amongst graduates has been observed in a number of countries. This paper takes as an example the UK, where the increase in inequality has been amongst the highest, to investigate any potential link between these two phenomena of participation and inequality. Dividing graduates by subject of degree to provide more variation, we show that most of the increase in graduate wage inequality has occurred within subjects. We investigate two potential explanations, specifically the increase in the variance of childhood cognitive test scores amongst graduates in the same subject, and the widening variety of jobs performed by graduates with degrees in the same subject. The paper shows that both of these factors have played a role in explaining growing graduate wage inequality within subjects, though the largest is by far from the increased variance of test scores. The results also show that mean test scores are falling over time within every subject to a greater or lesser extent, suggesting that the widening variance of test scores is due to universities accepting individuals from lower in the ability distribution, as Higher Education participation has expanded. •The growth in graduate wage inequality has occurred mostly within degree subjects.•This is related to an increased variance in ability of students within subjects.•It is also related to a wider range of jobs entered by graduates from each subject.•The first effect is more strongly associated with increased wage inequality.•Wider ability variance is due to increased participation of lower ability students.