Abstract
This article reports the results of an empirical study of the impact of school inputs on pupils' performance in private (independent) schools in the United Kingdom, using a new school-level panel dataset constructed from information provided by the Independent Schools Information Service. The authors show a consistent negative relationship between the pupil-teacher ratio at a school and the examination results achieved by pupils aged 18, controlling for the pupils' performance in examinations two years earlier. The results are noteworthy in comparison with results of studies for the state sector, relatively few of which have found a consistent and statistically significant effect of the pupil-teacher ratio.