Medium of Instruction Policies and Human Capital Formation: Theory and Evidence from Africa

The choice of language used to impart education can have important effects on the process of human capital formation. We develop a dynamic model to understand the implications of the choice of language used in education. The main contribution of the framework is to show that the number of years of primary schooling during which mother tongue instruction is provided might have non-linear effects on human capital. The marginal benefit to human capital in the provision of mother tongue instruction is seen to be positive for a certain duration of primary schooling, after which it turns negative. Panel data from 29 African countries support the conclusions of the model. The data show that the marginal benefit to human capital is positive and increasing for the first 4 years of primary schooling in the mother tongue and then turns negative. The data also indicate that providing mother tongue instruction for the first 4 years of primary schooling could increase average years of schooling in the affected cohort by around 0.80 years.