Ethanol and food prices

It is my understanding that the major byproduct of ethanol is distillers grains that are used as feed for cattle, hogs and chicken with essentially the same nutritional value as feed grains that have not had ethanol distilled out of them. All distilling ethanol does is remove the starch from the food grains and leaves the protein, etc, that animals need to grow.

This means that the use of corn or other feed grains being used to produce ethanol does not divert feed grains out of the food chain.

A bushel of corn can be used to generate x pounds of beef or it can be used to generate z gallons of ethanol and almost the same x pounds of beef.

Doesn’t this imply the argument I see on economic blog after economic blog that ethanol production is playing a significant role in higher food prices is incorrect.

Rather the Department of Agriculture and/or Bush Administration argument that ethanol production plays an insignificant role in the current run up in food prices is correct.

Does somebody have reasonable evidence that this analysis is incorrect?


The beauty of the new world of the internet.

while I was looking into this question I ran across a very good article by Richard Perrin at the University of Nebraska on Ethanol and Food Prices

Food prices in the U.S. rose dramatically in 2007 and early 2008. Given the integration of the world markets for foodstuffs, prices increased around the world as well, leading to riots in a number of countries in early 2008. The popular press has tended to attribute these food price increases to demand for corn by the ethanol industry. Grain prices are one determinant of food prices, but they constitute less than 5% of food costs in the U.S.(a higher percentage elsewhere.) This paper focuses on the likely relationship between ethanol and food prices, ignoring the potential role of other important contributors. It finds that ethanol is responsible for no more than 30-40% of the grain price increases of the last 18 months. Food prices in the US increased about 16% over the last five years,7% over the past 18 months, but rising grain prices have contributed only about a 3% cost increase over these periods. It is reasonable to conclude that ethanol is responsible for increases in US food prices about 1% in the last two years – a relatively small proportion of actual of U.S. food price increases. In food-insecure areas of the world,however, the impact of ethanol on food prices has been higher, perhaps as much as a 15% increase, simply because the typical food basket in those areas contains more direct grain consumption.

so I sent him an email with my question and he was nice enough to respond with this:

You are right. One-third of the corn processed for ethanol is expelled as distillers grains and solubles (DGS.) (One third is ethanol, one-third CO2.) DGS has slightly higher feed value than corn when it’s fed to ruminants (I have a publication with an animal scientist on this issue, if you become deeply interested, and could direct you to some others.) Since DGS can be directly substituted for corn, putting a ton of corn into an ethanol plant really only extracts 2/3 ton from the animal feed supply, so it would have been reasonable for me to assert that ethanol has accounted for only 30% of new net withdrawals of the world’s coarse grains since 2000 (rather than 40%.) China, Sub Saharan Africa, and South America are each responsible for about 15%.

So the standard treatment of ethanol in the press and blog is significantly misleading.