Estimating the impact of language of instruction in South African primary schools: A fixed effects approach

•In many countries, acquiring and learning in a second language is imperative.•We present empirical evidence on alternative language of instruction policies.•We use a unique administrative dataset from the population of South African schools.•First language instruction in grades 1–3 led to better English performance later on.•Using administrative data and fixed effects can allow important causal interpretations.

For many children around the world, access to higher education and the labour market depends on becoming fluent in a second language. In South Africa, the majority of children do not speak English as their first language but are required to undertake their final school-leaving examinations in English. Most schools offer mother-tongue instruction in the first three grades of school and then transition to English as the language of instruction in the fourth grade. Some schools use English as the language of instruction from the first grade. In recent years a number of schools have changed their policy, thus creating within-school, cross-grade variation in the language of instruction received in the early grades. Using longitudinal data from the population of South African primary schools and a fixed-effects approach, we find that mother tongue instruction in the early grades significantly improves English acquisition, as measured in grades 4, 5 and 6.