Does an aptitude test affect socioeconomic and gender gaps in attendance at an elite university?

The increasing use of aptitude tests as part of the admissions processes at elite English universities potentially has significant implications for fair access to these institutions. I attempt to isolate the impact of the introduction of one such test on the proportion of successful applicants by school type (as a proxy for socioeconomic status) and by gender using a difference in differences approach and administrative data from the University of Oxford. The introduction of the test coincided with the implementation of a guideline number of interviews per available place, significantly reducing the proportion of applicants offered an interview (by 14 percentage points) and, hence, increasing the proportion of interviewees offered places (by 3.6 percentage points). By gender, I find some evidence that these changes may be having differing effects at different stages of the admissions process, but not on each group's overall chances of securing an offer. I do not find any evidence that the policy has negative side effects on the chances of applicants from less advantaged socioeconomic backgrounds at any stage of the process.