COVID-19, college academic performance, and the flexible grading policy: A longitudinal analysis

•We find an income differential effect of the pandemic on college students’ GPA.•We use DiD models and event study analyses with individual fixed effects.•Low-income low-performing students outperformed their wealthier peers.•No such GPA advantage is observed among top-performing lower-income students.•Flexible grading counteracted negative shocks, especially among disadvantaged students.