We develop a model of international tariff negotiations to study the design of the institutional rules of the GATT/WTO. A key principle of the GATT/WTO is its most‐favored‐nation (MFN) requirement of nondiscrimination, a principle that has long been criticized for inviting free‐riding behavior. We embed a multisector model of international trade into a model of interconnected bilateral negotiations over tariffs and assess the value of the MFN principle. Using 1990 trade flows and tariff outcomes from the Uruguay Round of GATT/WTO negotiations, we estimate the model and use it to simulate what would happen if the MFN requirement were abandoned and countries negotiated over discriminatory tariffs. We find that if tariff bargaining in the Uruguay Round had proceeded without the MFN requirement, it would have wiped out the world real income gains that MFN tariff bargaining in the Uruguay Round produced and would have instead led to a small reduction in world real income relative to the 1990 status quo.

We investigate the welfare effects of vertical integration of regional sports networks (RSNs) with programming distributors in U.S. multichannel television markets. Vertical integration can enhance efficiency by reducing double marginalization and increasing carriage of channels, but can also harm welfare due to foreclosure and incentives to raise rivals' costs. We estimate a structural model of viewership, subscription, distributor pricing, and affiliate fee bargaining using a rich data set on the U.S. cable and satellite television industry (2000?2010). We use these estimates to analyze the impact of simulated vertical mergers and divestitures of RSNs on competition and welfare, and examine the efficacy of regulatory policies introduced by the U.S. Federal Communications Commission to address competition concerns in this industry.