Colonial Origins of Fertility Behaviours: Evidence on the Role of Forced Labour Migration in Burkina Faso

We study the case of Burkina Faso, the largest labour reservoir in French West Africa according to colonisers, who sent hundreds of thousands of young men to work in neighbouring colonies for one to two years.

Circular labour migration persisted after forced labour was replaced with voluntary wage employment: Burkina Faso is still characterised by large temporary migration flows to Cote d'Ivoire. We exploit the historical, temporary partition of colonial Burkina Faso (and, more specifically, the historical land of the Mossi ethnic group) into three zones with different needs for labour as a spatial regression discontinuity design.

We find that, on the side of the border where Mossi villages were more exposed to forced labor, there is more male migration, lower realised and desired fertility, and less polygamy today. As these villages are not richer, these long-term effects cannot be explained by an income effect.

Rather, they are consistent with the view that paid work opportunities outside the village disrupted traditional societies. Specifically, wage employment opportunities for adult men outside the sphere controlled by village elders reduced inequalities between men and the needs for child labor.

These findings contribute to the debate on the origins of family institutions and preferences, often mentioned to explain West Africa's exceptional fertility trends, showing that social norms on family formation can change if modes of production change.