African agricultural productivity and the transatlantic slave trade: evidence from Senegambia in the nineteenth century

Agriculture has played a central role in Africa's long‐term economic development. Previous research has argued that the low productivity of African economies has posed significant challenges to African efforts to produce an agricultural surplus or to develop commercial agriculture. Low agricultural productivity has also served as a key explanation for the transatlantic slave trade, on the basis that it was more profitable to export humans overseas than to grow and export produce. However, the field has suffered from a lack of comparable empirical evidence. This article contributes to this field by presenting quantitative data on historical land and labour productivity in Africa, from a case study of the agricultural productivity of Senegambia in the early nineteenth century. Focusing on five key crops, our results suggest that both land and labour productivity was lower in Senegambia than it was in all other parts of the world for which we have found comparable data. This article thus lends support to claims that stress ecological factors as one of the main determinants of Africa's historical development.