Working on trade policy issues, this book provides empirical evidence for effectiveness of U.S. antidumping measures under Byrd Amendment. The Byrd Amendment permits US firms that petition successfully for antidumping duties to collect tariff revenues. In a competitive market where domestic and imported goods are imperfect substitutes, the payments are akin to a production subsidy and thus undermine the duty’s ability to raise price. Applying the theory to the catfish war, antidumping measures taken by the US against Vietnam are shown to have had a modest yet positive effect on the US price. The Byrd Amendment is justified to enhance tariff effects on the US domestic price and trade flows under the Bertrand competition. The estimated increase associated with the duty is very small in price and sales of domestic fillets and insignificant on US farm price.