The Profitability of the Nantes Slave Trade, 1783-1792
Stein tests two rival claims about Nantes in the last decade of the old regime, that slaving made the port's fortunes and that it was a chronically losing business, by costing twenty-six voyages from surviving ledgers and merchant letters. The outcomes scatter: ten ships turned a profit, one broke even, six lost money. What separated them was neither the speed of the voyage nor the promptness of colonial payments, the two things the Chaurand brothers blamed, but the price of the outbound cargo and the number of captives a captain could buy on the African coast, both controlled by the firm itself. Around 950 to 1,000 livres laid out per captive marks the dividing line. Gross returns often passed fifty percent while net profit averaged near ten, half of that supplied by royal subsidies, and planters habitually withheld a tenth of what they owed. Slaving paid roughly what land or office paid, with a remote chance of a fortune.
Stein, R. (1975). The Profitability of the Nantes Slave Trade, 1783-1792. The Journal of Economic History, 35(4), 779-793.