Geopolitics and institutional change: the Napoleonic wars and the abolition of the British slave trade

Abstract

Britain abolished the transatlantic slave trade in 1807, shortly after it had become the uncontested economic and military power in the Caribbean. Why ban a profitable business in which its merchants were the dominant players? While the abolitionist movement is usually credited with this reform, this article shows that the geopolitical shifts caused by the Napoleonic Wars were central in mobilizing parliament to support abolition. British victories during the war brought new Caribbean colonies into the empire; colonies with vast, undeveloped land suitable for sugar cultivation and eligible for the same preferential tariffs as the old colonies. This threatened the economic prosperity of the older colonies, prompting them to support abolition in order to hinder the agricultural development of the newer colonies. The article shows that between December 1806 and February 1807, MPs with ties to the Caribbean economy shifted their support toward abolition in large numbers; I show that this change can only be credibly attributed to the economic threat posed by the new colonies. To examine the incentives faced by these MPs, I generate counterfactual sugar prices using a semi-structural model: sugar prices and plantation profits would have been lower if the slave trade had continued. The article shows that the Napoleonic Wars helped make the abolition of the slave trade possible, demonstrating how geopolitical shocks can lead to positive institutional change.