Huffington Post: A new study by University of Missouri Food and Agricultural Policy Research Institute (PDF) reveals that the current corn ethanol tax credit is effectively costing tax payers $4.18 per gallon and is driving up grain prices. The study estimates that the tax credit, which would cost about $5.85 billion next year if extended, will lead to 1.4 billion gallons above the 12.6 billion gallons required by law through the Renewable Fuel Standard (see page 64). In other words, next year the oil …