We report the results of experiments designed to test recent theories of vertical foreclosure. Consistent with the theory, the upstream firm has more difficulty commiting to supply the monopoly quantity in treatments with non-integration and secret contracts than in either treatments with...

We report the results of experiments designed to test recent theories of vertical foreclosure. Consistent with the theory, vertical integration improves the upstream firm's ability to commit to restricting output to the monopoly level, as does the use of public contracts. Public contracts are...