Explaining African ethnic diversity

The costs and consequences of ethnic diversity in Africa have been widely noted. However, despite Africa’s high level of ethnic diversity and its large internal variation, the sources of this diversity remain unexplained. Here the author shows that ethnic diversity in Africa is a result of its tropical location, the pre-colonial slave trade, the colonial creation of large states and low levels of urbanization. The effect of these variables are robust to various controls and specifications. He also shows that, once pre-colonial slavery is introduced, an African dummy variable becomes insignificant in regressions containing a world-wide sample of countries.