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

This study explores the impact of mother-tongue instruction in early grades on the performance of students later after they switch to English instruction. Students in Ethiopia switch to English-instruction classrooms either in grade 5, 7, or 9 depending on the state in which they attend school. Typically, this switch is from mother-tongue to English instruction for language-majority students and from second-language to English instruction for language-minority students. As a result, the intensity of the impact of the switch to English instruction varies by language group. Exploiting these two plausibly exogenous sources of variations across states and language groups and using data from a school survey, we estimate triple-differences model. The estimate from our preferred specification suggests that learning first in mother tongue (in grades $$1 - 4$$1−4) improves mathematics tests scores later (in grade 5) by 0.159 standard deviations, suggesting students taught first in their mother tongue learn in English better after they switch to English-instruction classrooms.