How home exams and peers affect college grades in unprecedented times

Leveraging administrative data from the University of Iceland, which cover more than 60% of the undergraduate population in the country, we examine how home exams and peer networks shape grades around the COVID-19 crisis. Using difference-in-difference models with a rich set of fixed effects, we find that home exams taken during university closures raised grades by about 0.5 points (≈ 7%) relative to invigilated in-person exams outside the pandemic period. Access to a larger share of high-school peers leads to an average grade increase of up to two-fifths of a point, and exposure to higher-quality peers yielded additional, but smaller gains. Interactions between peer-network measures and the COVID/home-exam indicators are near zero, providing no evidence that peer networks amplified home-exam gains during the pandemic.