The U.S. and Brazil are edging toward a trade war over ethanol. Brazil has imposed a tariff-rate quota (TRQ) on imported ethanol with the full backing of the domestic industry there, and the U.S. ethanol industry is pressuring the Trump administration to remove the preferential tariff treatment for a number of Brazilian goods (since there is no longer a tariff on imported ethanol). To put the matter into perspective, it is instructive to take a look at the history of the two key trade measures. In 2010, the Brazilian government moved to temporarily eliminate its 20 percent tariff on ethanol imports and to have the market open through 2011. The purpose was twofold: 1) help the country fulfill its biofuel use goals with imports since domesti...