We have never had the ethanol mandate and subsidies so the analogy does not hold. The ethanol mandates shifts the demand curve, impacting corn and many other crops. The past analogy involves only demand for food. Now we have demand for food and fuel. In addition, we have developing world demand. Thus, I do not see production catching up for some time if ever. A poor growing season will be disaster.
And yet they still won’t buy ethanol from Brazil because the “corn” lobby won’t allow it.
That's because you're professor and not a farmer.
Overproduction will continue to be problem. The real breakthoughs in yields are coming, better fertilizers usage through breeding, better drought resistance etc.
Corn production went from 6 to 7 billion bushels in 1985 to 13 billion in 2007. It will double again in less than 10 years with the current incentive to produce. Wheat, soybeans, name the crop, give the farmers the incentive that corn has to grow more, and you'll see the flood of crops continue.