A continuous income-based grade gap decomposition on university course grades

The earnings premium for education, and higher education in particular, is well documented. This article examines the college achievement gap between students coming from positions of high and low socio-economic status. Other papers have also looked at this issue, often by employing, at least in part, an Oaxaca decomposition. Past papers artificially divided socio-economic status into binary groups of high and low, in order to employ the decomposition. Socio-economic status is innately a continuous variable. Therefore, we implement a continuous version of the Oaxaca decomposition. Higher socio-economic students are both slightly better prepared in terms of observable characteristics and have better returns to their characteristics than lower socio-economic students. Notable differences across results obtained from the binary and continuous decomposition methods are discussed.