“…This allows us to control for unobserved factors that are fixed across assessment methods, in particular students’ academic ability. The same identification strategy has been used to investigate biased grading of students by gender (Lindahl, ; Lavy, ; Hinnerich, Hoeglin and Johannesson, ; Cornwell et al ., ; Di Liberto and Casula, ; Terrier, ; Lavy and Sand, ) and ethnicity (Burgess and Greaves, ; Botelho, Madeira and Rangel, ; Campbell, ).…”