Dr Elliott Green
Lecturer in Development Studies, LSE

Africa is widely noted for its high levels of ethnic diversity.  Indeed, numerous scholars have suggested that many of the continent’s problems such as authoritarian rule, civil wars and low levels of public goods provision are a result of its ethnic diversity.  These results, however, beg the question of why Africa is so diverse, and why the continent exhibits such a wide range of variation in levels of diversity from Liberia and Uganda at the upper spectrum to countries like Burundi and Lesotho at the lower end.

As such I investigated the sources of ethnic diversity in Africa in an article published in June in the International Political Science Review.  In the article I examined several potential reasons that could explain ethnic diversity in Africa from the pre-colonial, colonial and post-colonial eras.  From the pre-colonial era I found evidence that latitude is inversely correlated with ethnic diversity, such that countries closer to the equator have higher levels of diversity.  This result suggests that people living in tropical areas may not have needed to trade or interact with other people living far away from them due to a wide availability of food, which then led to isolation and the development of separate ethnic identities across time.

I also found that the early modern slave trade explains why Africa as a whole is more diverse than either Europe or Asia.  Drawing upon work by the economist Nathan Nunn, who estimated the number of slaves taken from various African countries up to the year 1900, I constructed similar estimates for other countries in Europe and Asia and found that a variable which capture the number of slaves exported per square kilometre was highly correlated with levels of ethnic diversity across Europe, Asia and Africa.  Indeed, in a series of regressions this variable completely eliminated the statistical significance of the notorious Africa dummy variable, which suggests that, had the slave trade not decimated the continent, Africa today might have levels of ethnic diversity much more comparable to parts of Western Europe and East Asia.

From the colonial era I found evidence that state size (in kilometres  squared) is positively correlated with diversity such that larger states are more diverse.  This finding might appear intuitive to Africanists, as ethnic groups on the continent tend to be territorially concentrated and therefore larger states would contain a larger number of ethnic groups.  However, in other parts of the world this relationship is not so straightforward, for instance if one considers caste or race diversity in India and the US, respectively, which in neither case is related to the size of the area being examined.

Finally, I examined the post-colonial period and find that urbanization is negatively correlated with diversity, such that increases in levels of urbanization between 1960 and 1985 are associated with decreases in levels of ethnic diversity over the same time period.  My research suggests that this relationship is driven by the way people adhere to broader sets of identities when they come in contact with each other in densely populated urban areas, a theory that goes all the way back to Marx and Engels’ Communist Manifesto in 1848.

The paper thus suggests that Africa’s high levels of ethnic diversity are not mysterious in origin inasmuch as they are a consequence of the early modern slave trade, and its large standard deviation in in ethnic diversity is the result of internal variation in latitudinal spread, state size and urbanization.  Especially as regards the last variable it offers a caution to researchers who would assume that ethnic diversity is fixed and unchanging in Africa, which is sadly still an assumption prevalent throughout the academic and non-academic literature.

Citation: Green, Elliott. 2013. Explaining African Ethnic Diversity. International Political Science Review 34, 4: 235-253.

Read the full paper (gated: http://ips.sagepub.com/content/34/3/235.abstract?etoc); (ungated prepublication version: http://personal.lse.ac.uk/greened/IPSR.pdf)