We want to study the transition from Admission post-bac to Parcoursup, which introduced a dose of selectivity in university admissions. We want to analyse the impact of the reform on the way than universities select applicants as well as student behaviour and outcomes. We want to understand how universities decided to select and rank applicants according to their grades, lycée, and department, as well as if these selection criteria differ across institutions. In particular, we want to observe whether universities learn to select students based on the success of past students with a similar background, leading to a concentration of certain student types across universities and programs. Then, we want to study the impact of this selectivity on student allocation and outcomes.