On the Size and Shape of African States

African states are both unusually large and well known for having artificial borders created during the colonial period. While African state size and shape have been previously shown to be correlated with negative development outcomes, no one has heretofore examined the origins of either phenomenon. Here, I show that African state size and shape are not arbitrary but are rather a consequence of Africa's low pre-colonial population density, whereby low-density areas were consolidated into unusually large colonial states with artificial borders. I also show that state size has a strong negative relationship with pre-colonial trade and that trade and population density alone explain the majority of the variation in African state size. Finally, I do not find a relationship between population density and state size or shape among non-African former colonies, thereby emphasizing the distinctiveness of modern African state formation.