The impact of learning in mother tongue first: evidence from a natural experiment in Ethiopia

This study explores the effect of learning in mother tongue first on students’ academic achievement later after they transition to English instruction. Even if Ethiopia has adopted mother-tongue instruction in primary school, its states have discretion to choose when students transition to English instruction. This results in a variation in the timing of the transition to English instruction across states in Ethiopia. Southern Nations, Nationalities, and People’s (SNNP) state, for instance, has legislated for students to transition to English instruction in grade 5 whereas students in other states in Ethiopia, except those in Gambella, do so either in grade 7 or 9. Due to the ethno-linguistic diversity of SNNP state, however, when students in the state progress from grade 4 to 5, the medium of instruction changes from mother tongue and second language to English for language-majority and language-minority students, respectively. This results in a variation in the intensity of the impact of the transition to English instruction by language group. Exploiting these two plausibly exogenous sources of variations (across state and language group) and using data from Young Lives’ 2012-2013 Ethiopian school survey, the study provides empirical evidence on the causal effect of learning in mother tongue first on students’ academic achievement later after they transition to English instruction by estimating triple-differences model. The estimates from the preferred specification suggest that learning in mother tongue first (in grades 1 − 4) increases students’ mathematics and literacy tests scores later after they transition to English instruction (in grade 5) by 0.269 and 0.089 standard deviations, respectively.