The effect of an anonymous grading reform for male and female university students

• The introduction of anonymously graded exams increased female students’ grades by 0.035 standard deviations relative to males at Stockholm University, indicating gender bias in grading. • The effect is driven by small classes and male-dominated departments, consistent with in-group bias and personal interaction theories. • A total of 1.83 million observations gives us enough power to detect the effect. • We use a difference-in-difference-in-difference (DDD) model, ensuring the results are causally identified and robust to multiple validity checks. This paper leverages a university-wide anonymous grading reform and presents evidence that female university students benefit from anonymous grading. Female grades improve by around 0.035 standard deviations relative to males. The effect is driven by smaller classes and male-dominated departments.