Ethnic geography and the colonial design of administrative units in Sub-Saharan Africa

Subnational administrative units are fundamental to territorial states and their political topography, but we know little about how their borders are designed. I argue that indirect rulers engage in preservation by ethnically aligning ad ministrative borders, which empowers peripheral actors. In contrast, central izing governments disrupt ethnic groups and their ability for collective action by splitting groups (dismemberment) and/or creating diverse units (suffoca tion). I test this argument by studying colonial administrative unit designs in Sub-Saharan Africa. I contrast indirect British with more direct French colo nial rule and use new historical data on administrative borders and ethnic geography. Modeling subnational borders with a probabilistic spatial parti tion model, I find strong positive associations with ethnic boundaries. These are stronger under British compared to French rule, which realized more ex tensive ethnic dismemberment but not suffocation. The results shed light on colonial administrative unit designs, thus highlighting the importance of unit endogeneity more broadly