Explaining African ethnic diversity

The consequences of ethnic diversity in Africa have been widely noted. However, the sources of this diversity remain unexplained, which is surprising in light of Africa's high level of ethnic diversity as well as its large internal variation. Here I show 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, and that my results are robust to various controls. I also show that controlling for the slave trade eliminates the statistical significance of an Africa dummy variable in regressions using data on global ethnic diversity.