The U.S. sustainability standard currently requires ethanol production to emit at least 20% less CO₂ than the gasoline it is assumed to replace. In a new study, authors Harry de Gorter and David R. Just argue that sustainability standards for ethanol are, by definition, illogical and ineffective. Moreover, say de Gorter and Just, those standards divert attention from the contradictions and inefficiencies of ethanol import tariffs, tax credits, mandates, and subsidies, all of which exist whether ethanol is sustainable or not.