How slave trade patterns explain African underdevelopment

Brad de Long points to an interesting paper by Nathan Nunn of the University of Toronto on African economic development and the slave trade. The paper, “Slavery, Institutional Development, and Long-Run Growth in Africa, 1400-2000”, seems pretty impressive. I’ve only glanced through it, but the reconstruction of the data for the exports of slaves over a 600 hundred year period is quite an accomplishment. The claim in a nutshell:

Can Africa’s current state of under-development be partially attributed to the large trade in slaves that occurred during the Atlantic, Saharan, Red Sea and Indian Ocean slave trades? Evidence from the historical literature suggests that the answer to this may be yes. This study attempts to answer this question empirically. Combining shipping data with historical records reporting slave ethnicities, I construct measures of the number of slaves exported from each country in Africa between 1400 and 1913. Using this measure, I find the number of slaves exported from a country to be an important determinant of economic performance in the second half of the 20th century. To address the potential problems of measurement error and unobservable country characteristics, I instrument slave exports using measures of the distance from each country to the major slave markets around the world. I also find evidence that the channel through which the slave trade affects development today is through the slave trade’s past impact on the formation of domestic institutions.

Nunn controls for ethnic fractionalization, Islam, Christianity, and primary resource extraction. He also shows that the effects of the slave trade are channeled through their institutional effects: political stability, the quality and accountability of the government, property rights. This of course makes sense in so much as we can expect huge and regular demographic upheavals to disrupt the ability of societies to solve collective problems in ways that benefit all and to open themselves up to predation by opportunists and marauders, inside and outside the state. For those interested, here’s another paper by Nunn outlining this mechanism (in game-theor-ese).

Despite the existence of empirical studies linking Africa’s current underdevelopment to its history of exploitation, a formal theoretical explanation of this link has yet to be made. How could these past events have had apparently lasting impacts? I provide a game-theoretic model that explains how extraction during the slave trade and colonial rule resulted in a permanent increase in rent-seeking behavior and a permanent decrease in the security of private property, both of which have helped foster Africa’s current underdevelopment.

The finds aren’t startling, but we do live in a world in which many have a tendency to downplay the hugely negative consequences of slavery for today and not merely for the past. As with all interesting work, more questions, I expect, will flow from these answers.