International trade agreements are an important element of the world economic system, but questions remain as to their purpose. The terms-of-trade hypothesis posits that countries use tariffs in part to improve their terms of trade and that trade agreements cause them to internalize the costs that such terms-of-trade shifts impose on other countries. This article investigates whether the most-favored-nation (MFN) tariffs set by World Trade Organization (WTO) members in the Uruguay Round are consistent with the terms-of-trade hypothesis. We present a model of multilateral trade negotiations featuring endogenous participation that leads the resulting tariff schedules to display terms-of-trade effects. Specifically, the model predicts that the level of the importer’s tariff resulting from negotiations should be negatively related to the product of two terms: exporter concentration, as measured by the Herfindahl-Hirschman index (sum of squared export shares), and the importer’s market power, as measured by the inverse elasticity of export supply, on a product-by-product basis. We test this hypothesis using data on tariffs, trade, and production across more than 30 WTO countries and find strong support. We estimate that the internalization of terms of trade effects through WTO negotiations has lowered the average tariff of these countries by 22% to 27% compared to its noncooperative level.

This paper studies the political influence of individual firms on congressional decisions to suspend tariffs on U.S. imports of intermediate goods. We develop a legislative bargaining model in which firms influence legislators by transmitting information about the value of protection, using verbal messages and lobbying expenditures. Model estimation using firmlevel data on tariff suspension bills and lobbying expenditures reveals that the probability a suspension is granted decreases with each additional firm that expresses opposition. This effect is significantly larger than that of either opponent or proponent lobbying due to the greater information content of verbal opposition and legislative bargaining costs.