Assessing knowledge or classroom behavior? Evidence of teachers’ grading bias

Abstract

This paper tests whether teachers unequally evaluate students based on their classroom behavior, rather than their scholastic competence. Evidence is drawn from a unique dataset on students from Brazil, which allows us to contrast teacher- and blindly-assigned scores on achievement tests that are high-stakes and cover the same material. We find that teachers inflate test scores of better-behaved students, and deduct points from worse-behaved ones. We also find that teachers’ decision to promote students is influenced by how they behave in class. Our results (i) document a potentially inefficient way of assessing students’ knowledge, (ii) explain a large part of grading discrimination against boys, and (iii) reveal a causal effect of noncognitive skills on educational outcomes that is unrelated to student proficiency.