The fast and the studious? Ramadan observance and student performance.

We examine how religious observance affects educational performance by studying the years in which Ramadan overlapped with the national end-of-secondary-school exams in the Netherlands. Using administrative microdata and a difference-in-differences design, we find that students who are most likely to fast obtain lower exam scores and are more likely to fail to graduate. As expected given the structure of the Dutch exam system, the increase in failure risk is concentrated among students near the pass threshold. Effects are larger in more religiously segregated schools. For longer-term outcomes, we document a substantially higher likelihood of dropping out among students aged 18 and older, who are legally permitted to leave school and therefore at risk of doing so. Finally, analyses of exam timing suggest that modest adjustments-such as avoiding scheduling two exams on the same day during Ramadan-may help reduce the disadvantages experienced by observant students. Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1007/s00148-026-01204-9.