Just because ethanol don't put a $5 bill in your pocket every morning don't mean it is not a boost to the economy. How about the workers at the plants? The trucks to get the corn to the plant? The railroads to get the gas in to mix with ethanol and ship the finished product out? The industries the produce the material to improve the roads around, to and from major highways around the plants and the material to build the sidings to get the product out? Darn right it boosts the overall economy. .
This is known as "The Broken Window Fallacy". Look it up.
A simple personal example:
When ethanol trashes someone's carburetor they bring the motorcycle to me to straighten it out. That boosts MY economy.
The flip side of that is the money is no longer in customer's pocket to boost someone else's economy. That's money that won't go to the corner restaurant, a new pair of shoes etc. In a very real sense my customer and the other people he buys from have been hurt to boost my economy.