The Consequences of Slavery in Africa

Nathan Nunn, an economist at the University of British Columbia, has written an interesting working paper called “The Long-Term Effects of Africa’s Slave Trade.” His abstract sums it up well:

Can part of Africa’s current underdevelopment be explained by its slave trades? To explore this question, I use data from shipping records and historical documents reporting slave ethnicities to construct estimates of the number of slaves exported from each country during Africa’s slave trades. I find a robust negative relationship between the number of slaves exported from a country and current economic performance. To better understand if the relationship is causal, I examine the historical evidence on selection into the slave trades, and use instrumental variables. Together the evidence suggests that the slave trades have had an adverse effect on economic development.

So Nunn finds that “the African countries that are the poorest today are the ones from which the most slaves were taken.” Does this mean, however, that the extraction of slaves caused those countries to remain poor? Nunn is careful to say that the evidence is not conclusive, since it may be that the African countries that were chaotic and corrupt enough to support the slave trade in the first place may have continued to suffer economically for those same reasons.

Regardless, it is a really interesting paper — and a good preamble, of sorts, to Fogel and Engerman‘s Time on the Cross, which argued that American slavery was less inefficient, and less miserable, than previously thought.

Nunn’s paper is also a good reminder that when many Americans think of Africa, they think of … well, Africa, a continent, as opposed to the many different African nations, each of which has its own set of bounties and problems.

Stan Preston

Isn't it just as likely that the areas targeted by European slavers had structural problems (such as lack of political organization, domination by nearby tribes with strong military power) that also impeded their later development?

And what about Arab slavers, who primarily affected the circum-Sahara and East African coast?


That's why I read this blog is to find interesting things to read. Thanks!

I wonder if it's possible that the results are somewhat similar to losing any export industry. If your economy is dependent on exporting X, and you stop exporting X, economic dislocation results -- such as a decline in employment. If, at the same time, you are seeing an increase in employable men (because you are no longer exporting them) this exacerbates the employment problem.

Gotta be a lot worse once you factor the huge family effects, though.


Do they control for European colonization, and its possible negative and positive effects?

(Could you even control for such a variable??)

Linda Loomis

This is slightly off-topic, but I was very surprised to recently read the following (p. 197) in the 2007 book by Brit Andro Linklater, "The Fabric of America: How Our Borders and Boundaries Shaped the Country annd Forged Our National Identity":

"Their revolt [American settlers in Texas in 1833] against the dictatorial rule of General Antonio de Santa Anna was not just about democracy but about slavery. In 1829, the government of Vicente Guerro had fulfilled the promise made in Mexico's Declaration of Independence and declared all slaves to be free. Mexico's loose confederate structure enabled the slave-owning Americans in Texas to ignore the ban at first. Then Santa Anna reformed the constitution so that power was centralized in Mexico City and in 1833 issued a decree banning further immigration of American settlers to Texas, while requiring slaves there to be set free. Thus the siege of the Alamo and Sam Houston's defeat of Santa Anna in 1836 were triggered by the need to defend not just Texas' liberty but their property in people."

UT Austin history professor H. W. "Bill" Brands does a great job explaining--I subsequently learned--the issue of slavery in Texas during this time period in his 2004 book "Lone Star Nation." But the point that galls me is: Why was I never taught this information about Mexico's slave policy during my education in California--elementary school through college?

And certainly neither actor Billy Bob Thornton nor actor Dennis Quaid leaned over and whispered this Mexico-Texas history to me when I attended the premiere of their movie, "The Alamo" in 2004. Ditto for actor Emilio Echevarria who played Santa Anna.



You could compare with central and eastern europe that also had a decent export of people to the mid-east and africa as slaves.

Rita: Lovely Meter Maid

I think it's a no-brainer that slavery is (and was) horribly bad for people. That's not to say that papers like Nunn's aren't important; they are. And it's not to say that slavery didn't have an up-side for someone; most likely it did for the slaveholders. If the slaves, themselves, sometimes found ways to live under that atrocious system in a manner that did not totally destroy them, that's probably very much because of their own ingenuity and inner strength, and not due to slavery's more easing properties.

George Smith

What about the fact that the social structure of Africa is not accurately representative by looking at the continent as a whole or even the muck up of border creation that was caused by European colonization?

Africa's largest problem is the fact that most of the outside world has no real understanding of the continent's true social make up and history and no real interest in discovering it.....


Loomis (#4) notes:
"Thus the siege of the Alamo and Sam Houston's defeat of Santa Anna in 1836 were triggered by the need to defend not just Texas' liberty but their property in people..... the point that galls me is: Why was I never taught this information about Mexico's slave policy during my education in California–elementary school through college?"

I remember the shock of this when it was covered in a college history class (this would be 1971 or so, in Missouri). But once you think about it, it makes so much sense. A huge amount of the larger political actions in the Americas is connected to slavery in some way (well, maybe not much if you are Canadian).

Derek G.

I'm from Texas. I was taught Texas History several times over, but I was never taught anything about slavery as a motivation to revolt. I suppose I had to take the Advanced Placement version of the class to get that information, because anything less is a cherry-picked, context-clumsy, slightly propagandized version.

To any parents out there who want their child to develop a thirst for history or at least a means of looking at the world with a bit more levelheadedness, be sure to enroll them in Advanced Placement History, be it European or American. I can imagine even the worst A.P. teacher to be loads better than the teachers and books that teach it at a "non-honors" level.

John Mark Rozendaal

In the nineteenth century U.S., slave-holders accused the abolitionists of hypocrisy on the grounds that industrialization abused and exploited laborers, de facto enslaving workers. This argument gains validity as we have seen globalization and the decline of labor unions steadily disenfranchise workers. Soon we must begin to see that injustice in labor relations in capitalist systems has many of the same evil qualities of chattel slavery.
Does focusing on the injustice and terrible consequences of slavery deflect our attention from other unjust relationships?

Karl Smith

Isn't it just as likely that the areas targeted by European slavers had structural problems (such as lack of political organization, domination by nearby tribes with strong military power) that also impeded their later development?

They instrument for this. In other words, they look at areas that would have been popular for slave hunters for geographic reasons and see if that is related to poverty, it is.

Moreover, a review of the data suggests the opposite, that Europeans targeted the most developed and stable areas. Probably because the population density was higher and the infrastructure for extraction was already there.

All in all its a pretty compelling story and an interesting story about institutions. Why for example Germany climbed back from WWII in a few decades but Africa has not recovered from the slave trade and Russia does not appear to be recovering from communism.



"Africa's largest problem is the fact that most of the outside world has no real understanding of the continent's true social make up and history and no real interest in discovering it….."

Well said!

I have to admit to being one of those who really isn't too terrifically interested in studying African cultures or history to a great degree. I have at least spent the time to become familiar with the history of the major areas of the continent. I also put forth enough effort to have an understanding of the cultures there that extends beyond a PBS miniseries.

IMO, you hit the nail on the head with your comment. Africa (yes the whole continent) has one massive problem, and that is other nations full of people with no interest whatsoever in respecting the sovereignity of the people and nations who have lived in Africa since before Europe had humanoid life!

As for the link between African slave trade and African poverty, well, look at the brilliant minds that have ended up in America because they were born from slaves. We have gained so much here in the US from the innovations of African Americans. Had there been no slave trade out of Africa, these engineers, chemists, physicists and so on, would have been in Africa and would have enriched their own land with their research and pioneering spirit.

That is something I do not see the abstract addressing, either; the tie between slavery and loss of intellectual minds needed for development and advancement in a society.


Henry Barth

I wonder whether the authors of the study considered black ownership of black slaves?

Black historian Carter Woodson found over 4,000 Free Blacks in the US who owned other blacks as slaves in 1830: "Free Negro owners of slaves in the United States in 1830."

I'm guess that blacks in African countries owned other blacks as slaves, and not only Arabs.

Rita: Lovely Meter Maid

#10, acknowledging one evil (slavery) does not mean that another evil is excused. Out and out slavery is when a person owns you and can have you put to death if that is the owner's whim. Anyone who is called a "worker", yet exists under such situations is really a slave.

Linda Loomis

Of course, our family's hands are not clean on the issue of slavery, a family member owning the last slave in Connecticut, Nancy Toney. I went to visit Toney's gravesite in the ancient Windsor cemetery in May 2004, but unfortunately the headstone was missing, perhaps stolen. An African-American woman who worked for the Windsor Historical Society walked the area with me that Saturday morning after I couldn't locate it, and together neither of us could find the grave marker at the rear of the grounds.


Nancy Toney was about 10 years old and ineligible for freedom when the state passed a gradual emancipation law in 1784. As a child she was given to the wife of Dr. Hezekiah Chaffee of Windsor and later became the property of Abigail, who reputedly took affectionate care of "Old Nance" in her dotage. When Nancy died in 1857, at age 82, she was, so far as is known, the last slave in Connecticut.



Here's a question I have no answer for:
What caused Europeans of the Enlightenment to turn against slavery? Certainly prior to that time, every historical society (including the Africans) enslaved the less fortunate of their own countrymen. Even in so-called "enlightened" societies such as the Greeks, Romans and Florentines, slavery enabled their intelligentsia to have the freedom from drudgery to pursue their creative pursuits.
I'll ask the economists: did the Industrial Revolution provide a substitute good for slave labor and did that precede or follow from the philosophies of freedom?


EB in comment #12 touched on this a little but the first thing that came to my mind was Darwinism. Slave trading was an industry and like any industry; sellers receive more money for the best product, in this case the biggest, strongest and healthiest men and the prettiest, lighter skinned, healthy, ability to bear children (although how you judge this is hard to say) in women.

So if a country's best, physically speaking, people are removed from a society what happens?

According to Darwinism, the society will eventually collapse and the strongest members will survive while the weakest go extinct.


#13: Yes, of course black African people owned slaves, often as the result of tribal warfare. That's how they had so many slaves available to sell to the Europeans in the African slave markets. Not everyone was tricked into visiting a slave ship by the promise of beads and trinkets.

But not all slavery is the same thing. Some Roman slaves were famously wealthy, well-respected, and protected by several laws and strong social rules. Mosaic law provides safeguards and limits on abuse of slaves -- a set of rules that compares quite favorably to the prevailing standards in NE Africa at the time. Most slavery of blacks in the Americas, however, represented the worst imaginable set of rules.


Wasn't slavery fairly common to begin with amongst African tribes? I remember reading back in my school days that when tribes squabbled the victor would often extract people as slaves back to their own community. I'm not sure I see the connection between the governing factions of the time when slavery was prevalent be considered the root cause of Africa's poor development. I'm sure that slavery is a factor in some ways, but I don't feel that it is the main cause of the rift that we see between "us" and Africa today.

Jonathan Conning

#16 asks: What caused Europeans of the Enlightenment to turn against slavery?
Well Western Europe had embraced serfdom over slavery most likely because it was a more efficient system (serf community could manage and farm lands and landlords could extract rents is a bit easier than landlord tries to organize production himself, particularly if he's become a landlord largely on account of his ability to be a good warlord so his farming skills may not be so good).
The reason involuntary serfdom collapsed in most places of Western Europe, according to economic historians like North and Thomas, is that Europe had a population crash following the Black death which forced landlords to compete for labor and raised the incentive for serfs to break loose. Fine story, except that its also true that involuntary serfdom was imposed or strengthened in Eastern Europe at about the same time, leading other economists such as Evsy Domar to argue contrary to North that serfdom and slavery is more likely where labor is scarce, since more rents are then to be earned by expending resources trying to pin down and own labor than owning land. Certainly African slavery in the Americas can be explained as an institution this way -- it was an institution tailor-made to solve the problem or labor scarcity in a land-abundant new region.