Power politics and the expansion of US exports, 1879–1938

In this article, we present quantitative evidence for the first time of the effect of US power politics on the expansion of its export market from the late nineteenth century to the eve of the Second World War. Like other empires, US imperial policy was expressed through annexation, gunboat policies, and asymmetrical trade agreements. We find that US exports to territories that became colonies or protectorates and those involved in other US military interventions grew more than three times faster between 1880–5 and 1934–8 than in the rest of the world. Our most relevant contribution to this discussion relies on a new geographically extensive database with information on bilateral trade flows, market size, trade costs, and variables that capture US political and military power. We first estimate a gravity equation to see the relationship between our power politics variables and US exports. Then, we present causal evidence of the role played by the colonies and protectorates in the expansion of US exports through an event study and the estimation of a generalized difference-in-differences model.