We report the results of an experiment that was designed to test for discrimination in grading in India. We recruited teachers to grade exams. We randomly assigned child "characteristics" (age, gender, and caste) to the cover sheets of the exams to ensure that there is no relationship between these observed characteristics and the exam quality. We find that teachers give exams that are assigned to be lower caste scores that are about 0.03 to 0.08 standard deviations lower than those that are assigned to be high caste. The teachers' behavior appears consistent with statistical discrimination.
Hanna, Rema N., and Leigh L. Linden. "Discrimination in Grading." American Economic Journal: Economic Policy 4.4 (November 2012): 146-168.