This study analyses whether teacher and test-based assessments differ systematically between low and high socio-economic status (SES) students throughout the Portuguese education system. As an indicator of the students’ SES, we use the level of education of the students’ parents. We use nationwide data on students and their assessments in 16 subjects in the 11th and 12th grades for a 10-year period ranging from 2009 to 2018. The analysis follows linear specifications to test whether there are significant socio-economic gaps between both grading schemes. The results suggest that, when comparing students with similar exam scores, the gap between teacher score and exam score increases for students from high-SES, suggesting that, for students with the same exam score, low-SES students have a lower teacher grade compared to their high-SES peers. Thus, exams seem to be relatively more favourable for students from low-SES and teacher assessment more favourable for students from high-SES.
