Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This paper argues that the value added score published for all publicly funded secondary schools in England is an unreliable indicator of school performance. A substantial proportion of the between‐school variation in the value added score is accounted for by factors outside the school's control. These factors include several pupil‐related variables such as the proportion of pupils on free school meals, the authorized absence rate of pupils and the proportion of pupils from ethnic minority backgrounds. The value added score is also related to several school characteristics such as the school's admission policy and its subject specialism. The main policy recommendation of this paper is that the value added score should not be used as a performance indicator, but should be used to gain a better understanding of why the value added score varies between schools.