Additional retake opportunities generally increase the probability of eventually passing a given threshold at given competence, and decrease preparation for exams. Preparation work performed before the first attempt may increase only for very weak students, and may decline so much as to decrease...

Frequent non-completion in optional education can be efficient if dropouts optimally exercise an option rationally foreseen by previous enrollment choices. This paper shows that in educational opportunities and groups of students where enrollment resolves more pronounced individual uncertainty...