What a difference a good school makes! Persistence in academic performance and the impact of school quality

In this paper we utilise a unique longitudinal school dataset from the Western Cape province of South Africa. We first explore the degree of persistence in the academic performance of learners over time in order to illustrate the importance of early detection of poor performance within the system. Thereafter, we make use of the longitudinal nature of the dataset in order to estimate the impact of school quality on academic performance following a fixed effects approach. We find that moving from a weaker school to a top performing school (a school within the top 20% of the performance distribution) is associated with an increase of 28% of a standard deviation in performance in mathematics, which translates to almost 1 additional year of education. For language, the impact is smaller at 6% of a standard deviation. However, this grows to 12% of a standard deviation for the sample of black learners, who might benefit the most from moving to a high performing school where the language used for instruction in all other subjects is taught well. These findings have important policy conclusions within the South African context, where school quality is heterogeneous and the weak performance of schools at the bottom of the performance distribution contribute to the perpetuation of poverty over time.