Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We compare non‐blind teacher assessments with blind national test scores in maths to examine teacher‐test score disparities by children's height and weight. Relative to test scores, shorter and heavier children are rated less favourably by teachers. This teacher‐test score discrepancy cannot be explained by the child's behaviours, motivation to learn or cognitive ability. Unobserved student fixed effects across subjects explain the teacher‐test score discrepancy by height, but not weight. Our analysis points to biased teacher assessments as the most plausible explanation for the remaining teacher‐test score gap by weight. We find harsher teacher assessments are associated with a reduction in both the child's future test performance and liking for maths 4 years later.