Being Bad by Being Good: Owner and Captain Value-Added in the Slave Trade

We use slave voyage data from 18th century Great Britain and France to answer two questions: 1) How important was the managerial quality of owners and captains in slave trading? and 2) What explains the substantial variation in managerial quality? Utilizing the Trans-Atlantic Slave Trade Database, in which we observe the performance of owners and captains in each of their voyages, we follow the teacher evaluation literature to estimate the value-added of owners and captains to slave voyage output, i.e. the number of slaves arriving in the Americas. Several results emerge. First, if we replace all owners with the 90th percentile owner in the country, slave voyage output would be 15% and 25% higher than if we replaced all owners with the 10th percentile owner in Great Britain and in France. This 90/10 ratio is 1.27 for British captains. Second, owner value-added is negatively associated with family businesses and positively associated with the level of competition. A comparison of owner value-added before and after the unexpected outbreak of the Seven Years' War, which historians suggest decreased (increased) competition in the French (British) slave trade, suggests competition's effect on owner value-added might be causal