Indeed...more demand than there is supply.
Is there?
Remember, 30 years ago we were paying farmers not to grow corn, to artificially keep the price up. No shortage back then.
The average price of corn over the last 10 years has been slightly higher than the fifty year average, but the 10 years before the average was lower. Did something ethanol related happen during that time that would effect the price of corn?
One thing did. Between 2012 and 2015 the ethanol mandate doubled. The price of corn also fell by half during that time.
Something else (AFAIK) non-ethanol related also happened over the last decade or so. The price of fertilizer exploded. Just an interesting example I picked up looking at the numbers.
Looking further back, between 1979 and 1986, US ethanol production went from 20 million to 750 million gallons. The price of corn during that time? Lower at any point in 1986 than any point in 1979, with the low in the fall of 1986 being a third of the peak in winter of 1980.
I'm not a farmer, just a guy looking at economic stats. "Common sense" says that if we force people to buy a commodity it will drive up the price of other products dependent on that commodity. But is there economic data to back up that assumption?