When are pupil absences most harmful for academic achievement?

Using linked data from the Millennium Cohort Study and National Pupil Database (N = 8,139),
this study examined how the timing of school absences (years 1 to 11 between 2006 and 2017)
affects achievement at the end of compulsory schooling in England. Absences during any
school year are harmful to student achievement. However, absences in years 6 (final primary
school year) to 10 (penultimate year of compulsory schooling) are between 1.6 and 2.0 times
more detrimental to academic performance than in other years. Every school year, authorized
absences hurt academic performance as much as unauthorized absences. To test the robustness
of our findings, we used comparable data and analytic methods for Wales and reached the same
conclusions. Our study points to the importance of addressing absences at every stage of the
school year to improve educational achievement for all students, particularly at the transitional
stages of primary to secondary school.