Endogenous Colonial Borders: Precolonial States and Geography in the Partition of Africa

We provide a new theory and evidence on colonial border formation in Africa. Existing accounts highlight that Europeans unilaterally drew arbitrary international borders in ignorance of local conditions. We instead show that African border formation was a dynamic process that lasted for decades, and propose that self-interested Europeans faced incentives to learn about and adjust to realities on the ground. The rough boundaries of precolonial states and salient geographical features (rivers and lakes) created focal points for Europeans to form borders and settle disputes, and also created leverage for African chiefs to influence colonial borders. To test our theory, we compiled original spatial data on precolonial states. Using both grid cells and ethnic groups, we test hypotheses about precolonial states and water bodies. We also compiled extensive data from treaties and diplomatic correspondences to show direct evidence of the mechanisms. We conclude that the colonial states were largely artificial with respect to historical and geographic antecedents—yet the borders between these states were not.