Politics and not economics drove the White House announcement today to approve year-round E15 fuel sales under an emergency waiver of the Clean Air Act’s requirements. Ethanol makes sense as an octane booster but less so as a gasoline substitute. Blending at the E15 level is already allowed in winter months and yet its use remains very low. The EIA has no measurement of E15 (or E85) use, but their best guess is 200 million gallons of E15, or 0.148 percent of all gasoline sold. Meanwhile, EIA says that “Almost all [95%] U.S. gasoline is blended with 10 percent ethanol.”  Corn only gained about 10 cents/bushel today despite a policy announcement that theoretically could have sent it into the stratosphere. Boosting etha...