Like a good beverage, a good book holds promise from the first sip. This extract is used with the permission of Tafelberg publishers.
About the author
Johan Fourie (photo: NB Publishers)
Johan Fourie is Professor of Economics at Stellenbosch University. He is a founding member of the African Economic History Network and president of the Economic History Society of Southern Africa. He has published award-winning peer-reviewed articles and is a regular columnist for local newspapers. His passion is to equip the next generation of African scholars with the skills to benefit from the data revolution.
About the book
How did Einstein help create Eskom? Why can an Indonesian volcano explain the Great Trek? What do King Zwelithini and Charlemagne have in common? These are some of the questions Johan Fourie explores in this entertaining, accessible economic history spanning everything from human migration from Africa 100 000 years ago to the pandemic. Join Fourie on this journey through an African-centred economic history and the story of our long walk towards a brighter future.
First sip
Who visited Gorée island on 27 June 2013?
The Atlantic slave trade and
Africa’s long-run development
Gorée is a small island off the coast of Dakar, Senegal. With its beautiful setting, including a small fishing harbour, it is easy to imagine the place as a summer resort for the West African rich and famous. But below its serene exterior lies a dark secret.
On 27 June 2013, one of the descendants of the people who suffered under this dark secret recounted her visit: ‘We saw the dark, cramped cells where dozens of people were packed together for months on end, with heavy chains around their necks and arms. We saw the courtyard where they were forced to stand naked while buyers examined them, negotiated a price, and bought them as if they were nothing but property. And we saw what is known as “The Door of No Return”, a small stone doorway through which these men, women and children passed on their way to massive wooden ships that carried them across the ocean to a life of slavery in the United States and elsewhere – a brutal journey known as the “Middle Passage”.
Michelle Obama, the former First Lady of the United States, is a descendant of Africans who were shipped to the Americas to be sold as slaves. In total, about 13 million people were forcibly shipped across the Atlantic from Africa between the sixteenth and nineteenth centuries. An estimated 1.5 million of them died en route.
How did such a cruel system arise? As we’ve seen in chapter 7, Africa has always had a high land–labour ratio. Because of the high demand for labour, women’s ability to reproduce and men’s ability to work the land were reflected in the cultural institutions that prevailed, such as bride price and slavery. Warfare in Africa was constantly a fight for labour, not land. Slavery was thus endemic to the continent, but, as Patrick Manning reminds us, it was small in scale.
Slavery can only exist if the captors have substantial resources and incentives to motivate their system of oppression. And it can only expand where there is significant demand for labour. Various factors can give rise to it, such as the presence of strong rulers with the ability to use force, the existence of markets for slave-produced goods, or the efforts of purchasers to transport captives some distance to where these conditions are met.
Although long-distance slave routes out of Africa had existed for centuries – such as the trans-Saharan route, the Red Sea route into Arabia, or the Indian Ocean route – all three conditions were only met after the Columbian Exchange – the transfer of products, people, plants and parasites across the Atlantic – had been established in the fifteenth century. By then, European traders had connected the fertile lands of the Americas with European demand for products such as sugar and coffee. To produce these commodities in the New World, the European conquerors needed labour – and Africa’s existing institutions of slavery provided the answer.47 With the assistance of African slave traders, often in exchange for guns that further facilitated the capture of people deeper into the interior, Africans were walked to the coast, to the slave ports where European slave ships would dock, waiting for their next shipment.48 It was under these harrowing conditions in the sixteenth century that the largest and most violent slave trade in human history was born. It would continue until deep into the nineteenth century, for a period of more than 300 years.
The Atlantic slave trade, as chapter 9 explains, shaped the development trajectory of the Americas in profound ways, giving rise to severe inequality in Latin America as well as institutions of exclusion that still permeate those societies today. Far fewer Africans ended up in the United States than in the Caribbean and Latin America (see Figure 11.1 for the ten largest Atlantic slave routes). But even in the US the legacies of the slave trade persist. In 1870, the income of African Americans was 25% of that of white Americans; by 2015, the number was higher but still a distant 65%.
The top ten slave routes, with number of known voyages, 1650s–1860s
Although much has been said and written about the consequences of slavery in the Americas, the question we want to understand better is how the Atlantic slave trade affected the development trajectory of the continent of Africa. Manning has estimated that Africa’s population would have been twice as big as it was by 1850 had it not been for the slave trade.
That is clearly a large shock, but just how these demographic changes affected economic development remained unclear until a Canadian student from the University of Toronto began to address these questions in his PhD project. In the early 2000s, Nathan Nunn, now a professor of economics at Harvard, used a comprehensive slave database and an innovative methodology to investigate whether African countries that suffered greater population losses because of the slave trade are poorer today than others. The novelty of this research lies in the causal claim of the question. Nunn not only showed a correlation between high slave export regions and underdevelopment today, but also demonstrated that the slave trade caused the underdevelopment.
How did he do this? He made use of an instrumental variable approach in his statistical regression analysis. It is worth understanding how this is done. Let’s say you want to know whether X causes Y. Finding a positive correlation does not, however, mean that it is X that impacts on Y. It could be something totally different, like Z, that affects both X and Y. Take the fact that umbrella sales in South Africa and ice cream sales in Belgium are positively correlated: if umbrella sales go up in South Africa, ice cream sales go up in Belgium. It is, of course, not that umbrella sales cause more Belgians to buy ice cream, or the other way round. It is a third factor – the weather – that influences both.
To identify causality, you need an instrument, one that takes another variable, D, into consideration, which is associated with X for some reason but has no reason to be associated with Y or Z or any other variable. If D is then found to be correlated with Y, then it must be because X is causing the variation in Y. Causality proved!
Imagine that X is the number of people taken from Africa as slaves. What Nunn first shows is that there is a correlation between this and the level of development today (Y). But, as we know, there could be many things that determine both the number of slaves taken and the level of development. For example, a high incidence of malaria (Z) could have caused poverty in 1500 (which then resulted in the removal of many people) as well as poverty today. What we need is to find an instrument that is correlated with X but should have no bearing on Y.
This is what Nunn identified. He used the distance from Africa to the Americas (D) as an instrument for the number of slaves exported (X). He showed that there is a high correlation between the distance (D) and the number of slaves taken (X). That makes sense: the European traders would have wanted to reduce transport costs (it was, after all, a profit-making enterprise) and would have chosen the shortest route to the Americas. That establishes the first condition of a good instrument. Secondly, there is no reason why the distance between Africa and the Americas (D) should have any effect on living standards in Africa today (Y); there is no reason that D should be correlated with Y. Yet this is exactly what Nunn found in his analysis. The result suggests that the Atlantic slave trade causally explains lower levels of development today.
Saying that slavery caused underdevelopment does not answer the question why. Nunn addresses that in two follow-up papers. The first, written with Diego Puga, argues that land ruggedness may be an important explanation. To protect themselves from the slave trade, Africans preferred to live far from the trade routes that were easily accessible from the coast. This meant that many lived in rugged and inhospitable areas. While this may have protected them against the slave trade, it also meant that they could not easily trade the surpluses that they were producing. As we have seen several times in this book, specialisation, surplus production and trade are essential to a thriving economy. Africans, through the very sensible decision to hide from slave traders, were constrained by geography, even after the slave trade ended. Consider that even today many of Africa’s capital cities are far from the coast.
The second explanation for the persistent effects of the slave trade on Africa’s development is trust. Africa’s internal slave trade was unique in that individuals of the same or similar ethnicities would often enslave one another. Nunn and Leonard Wantchekon use contemporary survey data to show that people whose ancestors were most affected by the slave trade in the past have lower levels of trust today, several hundred years later. This includes trusting relatives, neighbours, and even local government. Such a lack of trust has costs: in chapter 5 we discussed how important trust is to the process of solving the economic problems of production and distribution through the market system. Without trust between Africans there could be little trade and investment. Nunn and Wantchekon argue that the slave trade created these antagonistic cultural values and beliefs, which were passed on from one generation to the next, with detrimental consequences for Africa’s long-run development.
Reflecting on her experience of visiting Gorée, Michelle Obama wrote: "People who came through this island could never have imagined how history would unfold. And they certainly could never have imagined that someone like me – a descendant of slaves – would come here with her own family and look out through that door of no return." The Atlantic slave trade not only shaped the futures of the New World countries that these slaves would later come to call home but also irrevocably hurt the economic prospects of the continent they left behind.