Why did the United States subsidize American multinationals' entry into countries treated as informal colonies? We study a classic case of American imperialism, the 1903 U.S. support of Panama's secession from Colombia and subsequent U.S. payment of the 1921 reparations that opened Colombia's oil fields to Standard Oil. We test Noel Maurer's (2013) empire trap hypothesis quantitatively. Archival and econometric evidence documents Colombia's threat to Standard Oil's sunk investment, which induced the multinational to build a supermajority coalition in the U.S. Senate to back a reparations treaty. Results support the empire trap hypothesis but point out important qualifications.

Construction of the first transcontinental railroad, financed with large federal subsidies, is an important event in American history. Were the subsidies necessary to induce private investment in the railroad? The ex-ante investment decision examined uses contemporary reports and a simulation model to show that investors expected the railroad to be profitable. Evidence also shows that the railroad created political conflicts in Congress between the North and South. The secession removed the South as a disputant in Congress, reducing short-term political conflict but not long-term conflict. Subsidies reduced political risk, rather than transport market failure, and encouraged private investment.