Assessing causal effects of extra compulsory learning on college students' academic performances

In State Italian Universities candidate freshmen must take an entrance exam. Candidates who obtain a test score less than or equal to a prefixed threshold may enrol in the University but must comply with additional compulsory learning, named OFA (Italian acronym for Obblighi Formativi Aggiuntivi). The OFA assignment rule appeals to a (sharp) Regression Discontinuity (RD) design with the entrance exam score acting as forcing variable. In this paper we aim at assessing causal effects of the OFA status using data from a School of Engineering of a specific Italian State University. For sub-populations of units for which our RD design can be described as a local randomized experiment, we draw inference on the causal effects of OFA on students’ academic performances measured using two variables: the number of University credits awarded at the end of the first academic year and the corresponding average grade. These outcome variables suffer from the problem of truncation by “death”, because they are both not defined for students who decide to not enrol. Moreover, the average grade is also not defined for students who enrol but do not either take or pass any exam in the first academic year.