U.S. Corn Ethanol Policy - Northwestern University · Since 1980, government policy has been...
Transcript of U.S. Corn Ethanol Policy - Northwestern University · Since 1980, government policy has been...
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U.S. Corn Ethanol Policy The Recent Effects of Governmental Corn Ethanol Policy on Corn Pricing
Ben Brabston 5/17/2009
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Contents Acknowledgements.......................................................................................................................................3
Abstract.........................................................................................................................................................4
How Ethanol is Produced..............................................................................................................................5
Introduction ..................................................................................................................................................6
The Food versus Fuel Debate......................................................................................................................11
Literature Review........................................................................................................................................15
Other Areas of Research .............................................................................................................................19
The Regression............................................................................................................................................21
Equations ....................................................................................................................................................23
Data Sources ...............................................................................................................................................27
Results.........................................................................................................................................................28
Including Crude Oil Pricing..........................................................................................................................32
Conclusion...................................................................................................................................................36
References ..................................................................................................................................................37
Appendix .....................................................................................................................................................39
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Acknowledgements
In all honesty, when this paper was first being written, I had little intention of writing
acknowledgements. After hundreds of hours of work, my view has changed. An adviser is
expected to give a direction to a paper and to help the writer find the proper sources of
materials. Professor Kiesling has been much more than an advisor.
From day one, she has been nothing but a joy to work with. When times were tough,
and there were plenty, she kept my head square on my shoulders, gave me motivation to keep
working and always saw the glass as half full. The professional sound that this paper has
coursing through it is a product of her experience with writing these papers; experience that
she passed on to me. Would I recommend her to everyone? No, I would not do that to her. I
would only recommend her to the best of students.
To my friends and family, thank you for your understanding and support that I have
received throughout the research, writing, and revising of this thesis.
Enjoy the paper.
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Abstract
The food versus fuel debate has many sides. Recently Fortenbery and Park (2008)
analyzed the effects of ethanol production on the U.S. national corn price between December
1995 and November 2006. While previous work analyzed the effect of ethanol production on
gasoline prices, their work was a significant step towards understanding the broader
consequences of a growing trend towards using corn for ethanol.
Over the summer of 2008, corn prices spiked, and the Fortenbery and Park analysis
needs to be updated to account for this development. Key legislation on corn ethanol that was
passed in 2005 and 2007 is also not well developed in their regressions. Furthermore, they did
not analyze the effects of crude oil, a commodity highly involved in many economic activities,
on corn prices. This paper extends their analysis to include data through November 2008, as
well as providing analysis of the effects of crude oil price fluctuations.
The results show that the recession has had much more of an impact on the marginal
effects of corn ethanol production on corn pricing than government policy has had. Accounting
for the recession by including crude oil in analysis provides further support for this statement.
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How Ethanol is Produced
Ethanol is produced using two different methods, both of which employ inputs and
generate outputs that are relevant to the food vs. fuel debate and can be the subject of further
research.
The less common wet milling process starts by soaking the grain in sulfuric acid to
separate its components. The oil is extracted, and the other components, the fiber, gluten and
starch, are further separated by a centrifuge. These parts that are not used for oil are used for
feed and food (Renewable Fuels Association 2009).
The more popular way of making corn ethanol is dry milling. The more modern of the
two processes also exhibits economies of scale: dry mills can produce much more, require less
investment and capital to operate and are therefore more popular. In dry milling, the corn
grain is grinded into a "mash" and is cooked in water. Yeast is added to cause fermentation and
the resulting alcohol is distilled from 30 proof to 195 proof. The non‐alcoholic components of
the mash are then dried and used as feed (U.S. Department of Energy). About 30% of the corn
is recovered for feed in dry milling (Brown 2007).
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Introduction
Over the past three years the U.S. economy has experienced a series of unexpected
shocks. From foreclosures on housing to wars abroad to volatile gasoline prices, Americans
have found themselves in one of the worst economic situations in the past one hundred years.
One of the focal points of the recent economic crisis has been the food vs. fuel debate. As oil
prices have become more volatile, and America fights abroad, the U.S. has attempted to reduce
its dependence on foreign oil supplies. One solution has been to look to the heartland of the
country: at its home grown crops as a source of transportation fuels.
Many different grains can be used to create ethanol. In Brazil, for example, ethanol is
made using sugar cane. While sugar cane ethanol is often deemed a successful case of
supplanting oil supplies by using biofuels, the situation in Brazil is not easily replicable in the
U.S. because the U.S. does not grow nearly as much sugar cane, and because Brazil's aggregate
fuel usage is smaller than that of the U.S. Rather than use sugar cane for ethanol, the United
States' feedstock for ethanol is corn: nearly 95% of ethanol made in the U.S. comes from corn
(U.S. Department of Energy date unknown). Scientists are doing research into other crops and
products that can be used for ethanol, but the technology is not sufficiently advanced to be
used as a viable replacement for the current methods of producing ethanol.
Corn ethanol is made from corn kernels that go through a process of milling, drying,
mixing, and blending to create a final product that is generally added to gasoline to improve the
gasoline. Not only is corn ethanol burned with gasoline to fuel America's vehicles, but it is also
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an oxygenator for gasoline, making it burn more cleanly. There are many standard blends of
ethanol in gasoline ranging from E85 (85% ethanol by blend) down to the 5.7% standard
required in oxygenation programs (Duffield and Xiarchos 2008).
These current oxygenate standards and use of ethanol in fuel blends come from a long
line of governmental policy being written and rewritten. The U.S. government has been
involved in corn ethanol policy since the late 1970s. When the first ethanol policies were
established, it was argued that the government should be involved in corn ethanol policy for
multiple reasons: to establish energy independence (similar to the issues of today), to spark
economic growth in rural areas, and to reduce pollution caused by burning fossil fuels. Since
these arguments were based on public interest, the government felt that it was right to become
involved and to create its first tax exemption in 1978 for gasoline manufacturers that used
ethanol blended in their gasoline. At the time the exemption was $.40 per gallon of ethanol at
blends of 10% or higher. In 1980, the exemption was changed to a credit: it was the first motor
fuel credit for ethanol (Duffield and Xiarchos 2008).
Since 1980, government policy has been involved in corn ethanol production in a variety
of ways. Policies have involved changing the amount of the subsidy, creating tariffs on imports
of foreign ethanol, giving subsidies to small ethanol producers, changing the ethanol blend
percentages required to receive subsidies, and most recently creating the renewable fuel
standards (RFS). Today, the subsidy stands at $.51 per gallon for any percent blend of ethanol
in gasoline (Duffield and Xiarchos 2008).
More recent environmental policy has had major implications for corn ethanol policy as
well. When the Clean Air Amendments of 1990 were passed, one of the implications of the
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passage was the fuel oxygenate requirement imposed on petroleum refiners, which required a
certain percentage of oxygen in gasoline (2% oxygenation) (Duffield and Xiarchos 2008). This
requirement had two intentions: to reduce emissions of vehicles and to entice the production
of ethanol. Instead, the amendments led to a different conclusion. While harmful emissions
overall were reduced, the use of methyl tertiary‐butyl ether (MTBE) became popular amongst
manufacturers instead of ethanol because it fulfilled oxygen requirements, and it was cheaper
and easier to manufacture than ethanol. This would change.
In the following decade, corn ethanol policy once again was at the forefront of American
policy. While there had been discussion about the negative effects of MTBE, including it
potentially being a carcinogen, it was not until 2004 that it was finally banned in a series of
states at the beginning of the year, due largely to its effects on the smell and taste of water
when trace amounts of MTBE seep into ground water. In all, 40% of MTBE usage was cut
through bans in California, New York, Washington and Connecticut (Energy Information
Administration 2009). While there are oxygenate alternatives to MTBE and ethanol, such as
tertiary‐amyl methyl ether (TAME), ethanol found itself in a position where it appeared to be a
useful substitute and thus a highly sought after commodity (see figure 1).
The next year, the Energy Policy Act of 2005 put into place the most stringent corn
ethanol policy to date by creating a renewable fuel standard. The standard required that for all
gasoline produced, a certain percentage of ethanol must also be produced. While loopholes
allow for the use of imported ethanol, existing tariffs on ethanol imports protect the domestic
corn ethanol industry. An already quickly growing industry exploded.
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More recently, the Energy Independence and Security Act of 2007 created more
stringent guidelines for the RFS, as well as putting the EPA in charge of regulating the
percentage mandated by the RFS. It also made money available to look beyond the classic corn
ethanol production process to do research into cellulosic ethanol, which turns non‐food
products (cellulosic materials that are not digestible) such as corn stalk, tree bark, debris, trash
or branches into fuel. However, no major sustainable method of making cellulosic ethanol has
yet been commercialized.
Corn ethanol would not be as controversial if it were not for recent economic activity.
Lately, rising food prices have sparked a great food vs. fuel debate. Spikes in food prices and
especially corn prices have caused a sense of pandemonium across the world, including riots all
over the world over food prices and famously in Mexico over corn tortilla prices. In Mexico,
where many poor are forced to pay a third of their wages towards food, the price of corn flour,
the main component in tortillas, rose by 400% in a matter of three months (Taylor 2007). At
the core of the issue is how much the increased use of corn for fuel has caused food prices to
increase.
During the recession, many would expect prices to drop as the U.S. aggregate demand
would shift to the left. However, this has not been the case. The recent recession has caused
many equities and investments to appear much more risky, from companies collapsing, to
corporate and even municipal bonds being downgraded by Moodys, Standard and Poors, and
Fitch (Pascoe 2008). This effect has had two major causes. First, investments would drop as
overall confidence in the financial securities system declines and consumption might even rise
as a result. Second, alternative investments would become much more sought after. One such
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alternative is commodities. Over the summer of 2008, commodity prices across the board rose,
in part, because of the commodity bubble. Assuming it was this commodity price bubble that
caused prices to rises, many other factors affecting corn prices would have less of an impact
because bubble had such a strong impact. One such factor was the effects of ethanol
production on corn prices. Later in the paper, when crude oil prices are inserted into the
model, it is expected that the price of crude oil will account for some of the recession and
commodity bubble and drive the marginal effects of ethanol production on corn prices up.
How much does the increasing rate of production of corn ethanol affect the price of
corn? What have the recent policy implementations done to affect rising corn prices? What
caused corn prices to rise: was it the recession or government policy?
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The Food versus Fuel Debate
Corn ethanol production and the various commodity markets interact in ways that are
beyond the scope of this paper. Because corn ethanol production increases the demand for
corn, more land has been dedicated towards the production of corn. Not surprisingly, corn is
the main input into corn ethanol, and producers compensate for this new demand, by
dedicating more land to growing corn and reducing their production of other crops. This
production substitution causes the supply of corn to rise, while causing the supplies of other
crops to fall. Substitution also occurs towards the production of ethanol and away from other
uses of corn like food, feed and exports. The demands for substitutes for food and feed, such
as wheat and soy, are expected to rise. Figure 2 shows the effects graphically.
Corn and ethanol also require more inputs than many other crops (Olmstead 2007).
Fuel, which is often crude oil based, is an input in the production process of corn ethanol
because heat is used in the fermentation stage of ethanol production. Crude oil is also an input
for growing corn because it is used to fuel the vehicles on the farm and as part of pesticides and
fertilizers. These effects caused by the increased production of corn ethanol and field corn
drive the demand for crude oil up. Corn ethanol is also a substitute for crude oil in gasoline, so
the increased production of corn ethanol reduces the demand for crude oil. These conflicting
effects cause a shift in the demand curve, but the direction of the shift is a subject of possible
study. Ideally, the production of ethanol would drive the demand for crude oil down because
corn ethanol is argued to lower America's dependence on foreign oil.
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The food vs. fuel debate expands well beyond a basic argument of how prices for food
and fuel interact; it also encompasses the environmental implications of increased ethanol
production and consumption. These implications, however, remain controversial. One of the
arguments for using corn ethanol as opposed to gasoline is that corn ethanol is better for the
environment. Corn is a renewable crop grown from the soil and not a resource dug out of the
ground that replenishes slowly, so most of the carbon dioxide and other emissions released
from burning corn ethanol are reabsorbed by the corn that is being grown. The carbon cycle is
the basis for ethanol being a renewable fuel source: ostensibly the process of making ethanol
and burning it for fuel is a zero‐sum product process. However, growing corn is more energy
intensive than growing other crops, and corn uses other inputs, such as water, nitrogenous
fertilizers and pesticides, many of which are oil‐based. Another related issue is that the runoff
from growing additional corn for ethanol is causing a dead zone the size of New Jersey in the
Gulf of Mexico: an area where there is no oxygen and thus no plant or animal life (Olmstead
2006).
Producing corn ethanol also creates green‐house gases, and some estimates have
suggested that the reduction in green‐house gas emissions compared to oil in gasoline is less
than 15%, without taking into account the increase in emissions from producing more corn
(Olmstead 2006). In America and abroad, forests (and specifically rainforests in Brazil) and
reserve land, are being cut down and plowed at an alarming rate to satisfy rising demands for
ethanol. Moreover, some evidence indicates that the direct impacts of ethanol production on
global warming, such as deforestation, accelerate global warming by causing more emissions
than regular gasoline (AP 2009).
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The energy efficiency of corn ethanol relative to gasoline is also a subject of debate.
Traveling a certain distance requires 20% more ethanol by volume than gasoline to fuel a
vehicle. This disparity between the two fuels is called the volumetric difference because the
same volume of gasoline will fuel a vehicle farther than ethanol (Energy Information
Administration 2007). Because ethanol has lower fuel efficiency than normal gasoline, the
amount of green‐house gas reduction from using ethanol is less than often reported, because
going the same distance requires more ethanol than gasoline. Using gasoline blends with 10%
ethanol reduces green‐house gas emissions by a meager 2% (Runge and Senauer 2007).
Other issues arise, such as the sheer amount of corn needed to produce ethanol: the
corn used for ethanol to fill up one tank in an SUV could feed a person for a whole year.
Similarly, if all of the corn grown in the U.S. were used towards fuel, it would supply only 16% of
America's auto fuel needs (Brown 2007).
The food vs. fuel debate in the U.S. also has international implications. The use of corn
for ethanol not only has effects on prices, but it also has effects on demands: specifically, the
demand for exports of corn and the demand for corn ethanol. Since the two directly compete,
and corn is needed throughout the world for its starving inhabitants, corn ethanol has been
argued to be "starving the poor". Over two billion of the world's citizens live off of less than $2
a day, and of the 82 low‐income countries in the world, most are net exporters of oil, which
means that by reducing demand for oil by increasing ethanol consumption, America drives up
the price of one of their basic needs, food, while driving down the price of one of their main
products, oil. Some estimates suggest that the number of hungry people in the world will be as
high as 1.2 billion people which is 600 million people more than previous estimates: the reason
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for the increased estimates is higher food prices caused by increased demand for foods (such as
corn) used for biofuels (Runge and Senauer 2007).
The many points made in favor of corn ethanol include the obvious point that it is
environmentally sounder than using gasoline due to its renewability. The benefits of ethanol
consumption do extend beyond just the environmental effects of corn ethanol. Because it is a
substitute for gasoline, ethanol reduces America's dependence on foreign oil, a benefit that is
difficult to measure. Not only does it reduce the demand for imported oil, but it also increases
demand for domestic agricultural products, which until recently was generally viewed as a
positive development. The increased demand for agriculture leads to a stronger infrastructure,
and if developed enough the ethanol industry could potentially become as strong as Brazil's
sugar cane industry, which has helped Brazil’s economy develop substantially.
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Literature Review
A substantial body of work has analyzed many aspects of corn ethanol. Du and Hayes
(2008) examined and estimated the effective drop in gasoline prices caused by ethanol
production. Their work using panel and time series data results in explanations of the
correlation between the effects of ethanol production and gas prices. Their analysis indicates
that at one extreme in the Midwest, gas prices are reduced by $.39/gallon by the use of
ethanol. At the other extreme, in the Rocky Mountain region, gas prices are reduced by
$.17/gallon by the use of ethanol.
The United States Department of Agriculture (USDA) has published articles related to
the overall increase in costs per pound of different kinds of foods. Corn, the article explains, is
not a very expensive component in cereal, sodas (in the form of high fructose corn syrup), and
meats. Therefore, they argue that corn ethanol production is unlikely to be responsible for the
dramatic food price increases in 2008. Table 1 summarizes the results of the USDA analysis.
The article goes on to explain that sweet corn, which is used in corn on the cob and is
consumed directly by humans, makes up only 1% of the corn market, and of field corn, only
10% goes directly into human food. This table, however, does not reflect the effects of the
increased production of ethanol. By not performing econometric analysis, the USDA has
produced data that deliver little meaning because they do not account for the other factors
involved with the production of corn ethanol. Such factors include the income and substitution
effects and the supply and demand effects that result from the process of making corn ethanol.
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The income effect is the effect of changes in purchasing behaviors of consumers based
on different amounts of income. The income effect was especially relevant during the summer
of 2008, when many different commodity prices rose simultaneously, driving down the
spending power of consumers. A person that is able to spend $30 at a grocery store on their
dinner is more likely to purchase something nicer, like filet mignon, rather than a person who
has $5 to spend, who would be more likely to buy something less expensive like pasta. In the
summer of 2008 when all commodity prices rose, because these commodities were an input
into so many items purchased, there was a general income effect on the overall spending
power of the individual.
The substitution effect describes the changes in consumer behavior when prices change
for one individual bundle of goods. Because corn prices, which affect the bundle of goods for
which corn is an input, are volatile, many products that use corn as input have had price
changes. The combined income and substitution effects affect the supply and demand curves
of every good because depending on how prices increase or decrease, and how purchasing
power changes, consumers purchase different amounts of goods.
With less purchasing power in the grocery store, the demand for inferior goods (goods
that are purchased less when the income of an individual increases) will rise while the demand
for normal goods (goods that are purchased more when the income of an individual increases)
will drop. These two effects would shift the demand curves for both normal and inferior goods.
Under rising prices, to react to these demands, producers would be expected to streamline
their productions of inferior goods, causing supplies of inferior goods to rise, while, at the same
time, dedicating less effort towards producing normal goods causing the supplies for many
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normal goods to fall. These overall effects, which cannot be accounted for by basic pricing
inputs are the effects that need to be studied in order understand the entire range of effects of
rising corn prices.
Many other articles have focused on the world food shortage, which may be in part
caused by the production of biofuels. However, few articles address the American food
situation. Separating the two issues is difficult because of the interconnected world that exists
today. However, the focus of this paper is on the effects of corn ethanol on the U.S. national
price of corn.
Many articles make logical arguments without any numbers to back up their arguments.
The addition to literature from these sources is qualitative in nature and not quantitative. Their
points often provide explanation for what the basic numbers cannot. As journalist Alan W.
Dowd explains, rising demand for corn has resulted in more land being developed for corn and
less for other field crops. Increased corn production takes away land that is harvested for other
crops, such as wheat. As a result, the production of corn ethanol leads to other commodity
prices rising.
The most relevant research on this topic is that of Fortenbery and Park (2008), who used
a three stage least squares analysis to identify and estimate the effect of ethanol production on
the U.S. national corn price. Their work uses supply and demand equations to uncover the
effects of corn ethanol production. Their model will be used in this paper, the numbers will be
updated, and the equations slightly modified to capture more information. They discover that
ethanol was a major cause of the recent rising corn prices having a 16% marginal effect of
ethanol production on corn prices and accounting for a 41 cent per bushel rise over the course
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of the corn year from September of 2006 to September of 2007, which was about half of the
rise in prices that was witnessed.
Other possible models that are not used in this paper are investigated by Tomek and
Myers (1993) who wrote a paper discussing the different econometric methods for evaluating
commodity prices. All of the models have their drawbacks and none seem any stronger than
the model used by Fortenbery and Park. As a result, the three stage least squares model will be
examined throughout this paper.
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Other Areas of Research
This paper estimates the effects of ethanol production on corn price, but there are also
effects of ethanol production on other commodities, such as wheat and soy. As discussed
earlier, the recent trend to produce more corn ethanol has caused farmers to substitute their
land towards corn and away from other crops, or they have started farming land that was
previously untouched. Either way, there is an effect on the supply side of other crops caused
by corn ethanol production.
Ethanol production affects pricing of meats, such as beef, pork and chicken. Similar to
other commodities, the effect of corn ethanol production would be seen on the supply side for
meat, since corn is a major source of feed for livestock. Farmers have given testimonial that
explain that the rising price of corn (which is in part caused by ethanol production) forces
farmers to substitute towards lower quality feeds, and/or farmers must charge more for their
meat to keep up with the rising corn and feed prices (Moody 2008). Research into the effects
on quality and prices of meat would provide insightful results.
The production of corn ethanol itself affects certain inorganic commodities as well. As
stated above, fuel and water are both inputs in the production of ethanol. Demand side effects
involving corn ethanol complicates research and models even more.
Unfortunately, quarterly data are not available for most of these items. The demand for
water and oil is no doubt very complicated and often affected by factors that econometrics has
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difficulty accounting for, such as the endogenous effects of OPEC, and the USDA data for wheat
and soy do not extend far enough back in time to research these areas thoroughly.
Other areas of potential study include those of the actual effects of rising corn prices on
the costs to consumers in the grocery store. The USDA (Leibtag 2008) report does not include
any of the substitution effects discussed above, and simply analyzes how much corn is used per
item (see figure 6 in appendix). Analyzing the effects of corn prices on everyday items would
require a special knowledge of the subject and an understanding of all commodity markets that
are beyond the scope of this paper. Furthermore, the production of ethanol requires a great
deal of inputs like water and fuel. This, in turn, will drive up the costs of water and items that
require water to work: an unintended consequence of corn ethanol use. These effects cannot
be measured in corn price increases.
The issue of the byproducts of corn ethanol production should be researched as well.
The idea that corn that is used for ethanol is not used for anything else, like feed, is skewed.
There are byproducts of corn ethanol production that are used as both feed (for animals) and
food (for humans). A possible avenue of further research into the underlying feed demand
effects of corn ethanol production is a possibility.
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The Regression
The goal of this analysis is to examine the effects of corn ethanol production on corn
prices. Specifically, the paper hopes to analyze the effects of the recession combined with new
government policy. Ultimately, the paper hopes to attribute the recent increase in corn prices
to either the recession or new government policy.
The sources of the data in this paper are meant to emulate those used by Fortenbery
and Park. As their model explains, the supply and demand in the commodity market for corn
are represented in four equations: one equation for supply and three equations for the
different demands for corn: feed, exports, and food, alcohol and industry (FAI) as described by
the USDA (see figure 3). The demand for food, alcohol and industry is described as a single
demand, and it contains the production of ethanol. Because the price of corn is an
independent variable in all of the equations simultaneously, a simple ordinary least squares
calculation will not result in unbiased coefficient estimates. Rather, a three stage least squares
is used to address the endogeneity of price in the entire model.
Three stage least squares builds off of the two stage least squares concept. A two stage
least squares estimation uses a basic instrumental variable to solve for an endogeneity issue in
one equation. However, this model has four endogenous quantity variables: the supply of corn,
the demand for feed, the demand for exports and the demand for FAI. The price of corn is
determined by the previous inventory (supply), the three demands described above, the
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previous price of corn, and quarterly dummies to control for seasonality effects and other
omitted or unobserved variables.
The previous price of corn is used as a Markov Chain component. A Markov Chain is
defined as any stochastic process that is affected by the most recent piece of information and
nothing prior to the most recent piece of information – the most recent observation captures
all of the relevant historical information. In other words, a stochastic process is a Markov Chain
if:
Where the s represent time. Simply put, the entire regression is a large Markov Chain.
Three stage least squares estimation combines the five equations (one for price, one for
supply, and three demands) to account for the endogenous determination of price and quantity
across these interrelated markets. It uses a series of instruments (not just one in the two stage
least squares method) to explain the price equation.
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Equations
All of the following variables are expressed as logs in order to determine percentages
with the exceptions of quarterly dummies and time trend variables.
The supply equation is as follows:
Where is the inventory (or supply) of corn at the beginning of each quarter. The first
quarter is defined as September of the current year as that is when the previous year's crop is
harvested. The current year's crop is planted in the third quarter. Supplies act in an annual
fashion, increasing once during the first quarter after the harvest (resulting in the highest corn
stock being recorded during the second quarter) and then dropping throughout the year. The
coefficients, and (on the previous quarter’s price of corn and the interest rate
respectively) are expected to be negative because the higher price of corn, and the higher the
holding cost, the more willing farmers are to sell their corn. The coefficient for the previous
supply, is expected to be positive.
Each equation has dummy variables to account for quarterly trends, such as the trend
for supplies to spike in the second quarter and then dip as the year goes on.
The feed equation is as follows:
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Where is the quarterly consumption of corn for the purpose of feed. The price of corn, , is
found in every demand equation and it is always expected to have a negative coefficient in
demand equations. The price of soymeal, , a substitute for feed corn, is included and
expected to have a positive coefficient. , , and represent the number of broilers
(chickens), cattle on feed and hogs respectively and are expected to have positive coefficients.
The export equation is as follows:
Where is the quarterly amount of corn exported. The wheat production of the rest of the
world, , and the dollar index, , are expected to have positive coefficients. The Dollar
Index is included to account for exchange rates against eight major currencies in the world.
is a weighted measurement of the GDP per capita of the five main importers of wheat
from the U.S.: Japan, Mexico, Taiwan, Egypt and South Korea. It is expected to have a negative
coefficient because the higher the GDP that these countries have, they presumably import less
and export more. As Fortenbery and Park point out, these five countries account for more than
60% of the United States' corn exports.
The consumption of corn for food, alcohol and industrial use (FAI) equation is as follows:
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Where is the quantity of corn consumed for food, alcohol, and industry. The amount of
ethanol, , is provided by Energy Information Administration and will have a positive
coefficient. The United States population, , is included as well. A time trend, , is also
included because FAI demand has grown greatly and consistently over the given time period
(see figure 4). During the same time period, ethanol production grew consistently as well. To
avoid ethanol production being credited with excessive weight on the growth of demand for
FAI, the time trend is added.
A regression that involves a Markov Chain and the supply and demand for corn derives
the formula for price. Specifically, the demand is broken down into its three components from
above. The price equation is therefore:
This equation involves five endogenous variables, but the endogeneity issue is solved by the
previous equations describing the different supplies and demands. The coefficient on supply is
expected to be positive, and the demand coefficients are expected to be negative. While there
is an issue because the coefficient on the demand for feed is negative this is presumably caused
by the fact that when feed amounts are measured, they also include residual amounts of corn
consumed, so these numbers aren’t as precise as the export of FAI numbers. Once again,
quarterly dummies are included since corn production operates in a cyclical fashion.
The final price equation uses all of the instruments provided to make the final equation:
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where
To see the overall results of the regression, see Table 2.
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Data Sources
Most price, production, stock, livestock data, and corn usage are obtained from
different USDA sources. The corn price is a measurement of the quarterly average of the USDA
monthly reported average farm level price. The soybean meal prices came from Index Mundi, a
website dedicated to providing country profiles. Corn stocks are measured from the USDA
quarterly stock reports, and represent the size of beginning stocks as of Mar 1, Jun 1, Sep 1, and
Dec 1 of each year.
The variables used to explain consumption of corn for feed, exports and FAI come from
the USDA as well and are also measured quarterly. The amount of cattle on feed and hogs are
the quarterly averages of monthly data, and the amount of broilers is the quarterly average of
weekly data.
The dollar index is found on the web site of the Board of Governors of the Federal
Reserve System. The GDP per capita for importing countries data is from the International
Monetary Fund, and data for the U.S. population comes from Econstats.com. Both are constant
during a year. GDP per capita is the annual number evaluated in current U.S. Dollars. Ethanol
production is taken from Energy Information Administration, and is the quarterly sum of
monthly production.
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Results
Since the regressions are log‐log regressions, we can use the following to describe the
overall effect of corn ethanol production on the price of corn:
Therefore, the ethanol production elasticity of corn price is:
This estimate is different from the result of the Fortenbery and Park analysis (.16). The result
suggests that an increase by 100% in the production of corn ethanol will result in a 10% corn
price increase in the short run.
The most likely reason for the differences across the two estimates is the sources of
data. Since many different variables are used and modified, from different sources, this is not a
surprise. The main argument of this paper does not rest on proving or disproving Fortenbery
and Park. Rather the paper makes its findings by comparing relative changes over the different
time periods and by bringing crude oil into the picture.
What is important is modifying the data range. Fortenbery and Park use the time period
from the 2nd quarter of 1995 (December, 1995) to the 1st quarter of 2006 (November, 2006).
However, this time period does not include the period of greatest volatility of corn prices. From
29
the 4th quarter of 2005 (June, 2006) to 1st quarter of 2008 (November, 2008), prices ranged
from $2.12 per bushel (in 4th quarter of 2005) to $5.33 per bushel (in 2nd quarter 2007): 250%
of the price that it was less than three years before. To disregard this great variance is to leave
out a great set of data. Different results are expected when the very same regressions are
rerun while using a different time period: from the 2nd quarter of 1995 to the 1st quarter of
2008. See Table 2 for the results of the regression from the new time period. Despite new
government policy mandating the production of higher amounts of ethanol, the recession has
had a much bigger effect on corn prices than government policy. The marginal effects
calculated from the newer time period are:
The drastic drop in marginal effects of corn ethanol production on corn pricing, from .10
to .03, is explainable. The downward shift in marginal effects is credited to the recession for
reasons explained below, while if there were an increase in marginal effects (which there is
not), this would be credited to government policy having a greater effect than the recession.
The strongest possible explanation of the drop in marginal effects is that because corn
prices increased so quickly over the summer of 2008, and ethanol production did not rise nearly
as much, corn ethanol production could not account for the higher rate of increases in the price
of corn. Corn, like many other commodities, became a relatively expensive commodity, and the
main reason for this was the recession. During the recession, many assets became riskier, and
commodities were seen as a safe set of items to invest in. Since commodities became a
suddenly more valuable asset, the price of all commodities shot up (see figure 5) (Pascoe, D.
30
2008). Assuming the commodity bubble was the cause of the rise in corn prices, many of the
other factors affecting corn prices would be weaker. In other words, the marginal effects of
almost all of the other variables would tend towards zero since an externality not captured in
the model (the recession) affected corn prices. This is the result: the marginal effects of
ethanol production on corn prices decreased, tending towards zero because an externality, the
recession, had a stronger impact on corn prices than government policy, which would have
driven the marginal effects up. Therefore, the cause of the rise in corn prices was the
recession, not any single factor like the production of corn ethanol. As expected, overall the
coefficients for the supply and the demands tended towards zero (with the exception of
exports, which also had by far the lowest R squared values) relative to before because the
overall effect of the recession could not be measured simply in supply and demand
characteristics.
Unfortunately, because of the recession, the effects of the Energy Policy Act of 2005 and
Energy Independence and Security Act of 2007 cannot be isolated since both coincide with the
recent recession. The result of the regressions explains that the recession (which drove corn
prices up) had a much more substantial effect on corn prices than government policy did.
Without the recession, it would be expected that policies would cause the marginal effects to
remain the same if not rise above what they were previously.
There are two main reasons for this. As stated, these effects were not witnessed
because of the recent recession. First, the renewable fuel standard was a demand shock,
causing FAI demand to increase dramatically. This FAI‐specific demand shock would drive the
demand for FAI up, and thus also the effect of FAI on corn prices, causing the overall marginal
31
effect of corn ethanol production on corn prices to rise. Because the regressions are run over
different time periods, the more updated regression accounts for more data points after the
passage of the Energy Policy Act of 2005 and the Energy Security and Independence Act of
2007. Therefore, the overall effect of the policies would weigh more heavily on the regressions.
Furthermore, because the demand shock was unexpected and farmers did not have
time to adjust the crop distributions of their fields, the amount of corn required for ethanol
would rise without farmers being able to readjust supplies. This timing would exacerbate short‐
run price increases by causing a shortage of corn. However, these effects did not materialize
because the effects of the recession dominate the effects of the recent government policy.
32
Including Crude Oil Pricing
Crude oil and corn markets are interrelated because crude oil is a significant input into
corn production, in the use in fertilizers and pesticides and the fueling of machines required to
plant and harvest corn. Crude oil is also involved on the demand side: specifically in the
demand for FAI, because ethanol is a substitute for crude oil, and crude oil is a fuel source that
can be used in the production of corn ethanol. Especially in the past few years, oil prices, like
corn prices, have increased dramatically. See figure 6 as evidence of this. As stated above, the
main cause for the drop in marginal effects was the recession. Without the recession, it is
expected that the marginal effects would stay the same, if not rise. Not only is oil involved in
the demand for corn, but it is also a decent indicator of the recession, as it was in the 1970s, so
there are a few reasons to include oil into the model (Stein 2009). Oil was affected by the
commodity bubble over the summer of 2008 as well.
The question is how to include oil prices in the model. As stated, oil is involved in both
the production of corn and the demand for FAI. However, the supply of corn in this model is
different from the production of corn because supply numbers are measured in terms of the
stocks of corn. Oil prices affect the production of corn, but not the current year's actual stocks,
which are what is measured. Therefore, the effects of oil on the production of corn can be
ignored (although there is no doubt that long term elevated oil prices will reduce the amount of
corn grown and harvested and thus have effects on the stocks). The model predicts short term
marginal effects and not long term effects, so the price of crude oil is included in the demand
33
for FAI. Granted, there are issues involved with oil and the demands for feed and exports, but
these effects are ignored for the simplicity of the model and because oil has a much greater
impact on the demand for FAI.
The recession impacted many different commodities. Oil does not exhibit a lot of the
supply and demand endogeneities of other crops because it doesn't compete with corn on the
supply side. Furthermore, elevated oil prices are an indicator of the recession. For these
reasons, oil is an important component to use when trying to account for the recession.
Running a quick ordinary least squares regression shows the strong positive relation
between crude oil prices and corn ethanol production:
As expected, the equation has a very positive, significant value for (.89) with a
relatively high R squared: .68. The data for the price of crude oil is found on the Energy
Information Administration's website and is the average of the monthly prices across each
quarter. With this in mind, the new FAI demand equation is adjusted as follows:
As done by Fortenbery and Park, a Breusch‐Godfrey Lagrange Multiplier test is run for
autocorrelation, and the new equation exhibits no autocorrelation. The rerun three stage least
squares estimation produces greatly altered results. While the actual coefficient for the price
of oil is insignificant, the effect on the marginal effects is substantial and expected. It is quite
34
possible that the use of oil as a substitute for ethanol and the use of oil in the production of
ethanol amalgamated to make the coefficient on the price of crude oil insignificant.
The concern of this paper is not the actual coefficient on oil, but, more importantly, the
effect of including the crude oil variable. The equations take into account a direct substitute for
corn ethanol and also account for part of the recession. Other variables, like the U.S. Dollar
index and the amount of corn exported, are related to effects of the recession but do not
effectively account for the recession and the commodity bubble like the price of crude oil.
Table 3 summarizes the results of the regressions using crude oil pricing.
Using the 1995 – 2006, the following elasticity is derived:
Using the 1995 – 2008 data, the updated elasticity is .06:
Overall the marginal effect of ethanol production during the 1995 – 2008 time period increases.
In fact, the gap between the marginal effects decreases between the 1995 – 2006 and 1995 –
2008 time periods. This result is expected: including the crude oil price has brought the
marginal effects of the two time periods closer together because the recession is more
accounted for by the crude oil price variable.
Another result of including oil in the regression is that the coefficients on the other two
demand equations, feed and exports, tend to zero relative to the regressions that are run over
the same time period without the oil variable. This is also expected because accounting for the
35
cost of oil also takes into account for what these other demands were originally accounting for:
trends in the economy. While oil is not a perfect indicator of the situation of the economy, it is
generally associated with a boom or recession. Therefore as expected, even though the actual
coefficient on the price of oil is insignificant, it has a noticeable impact on the overall pricing
equation of corn because it captures a lot of economic activity that the demands for feed and
exports were previously capturing.
Interestingly, the price of oil has very little effect on the regressions when the
regressions are run over the time period of 1995 – 2006. This is also expected. During that
time period (even during the recession in 2001) the economy was much more stable, so the
recession effects captured by the price of crude oil are not noticed. Therefore, the price of
crude oil has little effect on the results from this time period. This indicates that the price of
crude oil has much more of an impact by capturing effects of the recession than being a
substitute for corn ethanol.
36
Conclusion
Fortenbery and Park’s paper is an important step towards understanding the effect of
the production of corn ethanol on the pricing of corn. Unfortunately, a combination of recent
occurrences in the U.S. economy and new government policy has resulted in their results being
quickly outdated. The time period of study for the two authors was one of little economic
turmoil, and thus the period of study does not need to account for the recession or the
commodity bubble.
When the very same regressions are examined, using a more recent time period, the
results are significantly altered. The recession has had a much greater impact on the pricing of
corn than government corn ethanol policy. As a result, the marginal effect of ethanol
production on corn price decreases.
An attempt to account for the recession using crude oil prices does explain that the
recession has caused the marginal effects to drop. Further analysis on the recent recession
should be done to totally account for the recession. Perhaps with the full effects of the
recession accounted for, the true effects of government policy will be revealed.
37
References
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International Monetary Fund. Available at http://www.imf.org.
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39
Appendix
Table 1: Effective price rise in components of goods due to corn price increases
% Price Increase due to 49% corn price price going from $2.28 to $3.40/bu, a 49% increase in price
18 ounce box of Corn Flakes .5%
Coca Cola 2 liter 1%
Chicken Breast 2.5%
Beef 8.7%
Pork 4.1%
Source: http://www.ers.usda.gov/AmberWaves/February08/Features/CornPrices.htm
40
41
42
Ethanol Effect on Corn Ethanol Effect on Wheat, Soy, etc.
P P
Q Q
S'
S'
SS
D D
D' D'
Fig. 2 Expected Effects of Increased Corn Ethanol Production on Other Crops
43
44
45
46
47
48
Table 2: Basic regressions
Data from 1995 – 2006
Data from 1995 ‐ 2008
Coefficient Standard Error Coefficient Standard ErrorPrice Constant 1.871 2.348 ‐1.464 1.927
.210 .144 .143 .101 ‐1.002 .238 ‐.508 .222 .010 .115 .385 .1 .191 .11 .069 .101 .877 .176 .880 .118 1.086 .241 .575 .203 .487 .198 .282 .184 .256 .108 .167 .010
Supply Constant 16.009 1.79 7.433 1.644 ‐1.214 .157 ‐.246 .109 ‐.019 .035 ‐.064 .044 .002 .109 .507 .103 ‐.953 .088 ‐.651 .095 .802 .178 1.606 .171 .474 .074 .317 .086
Feed Constant ‐9.264 3.641 ‐2.145 1.668
‐.407 .087 ‐.219 .065 .228 .060 .155 .063 .042 .162 .273 .194 .299 .19 .643 .186 1.078 .338 ‐.060 .031 .877 .026 .907 .029 .574 .033 .533 .033 .301 .029 .265 .028
49
Exports Constant 13.416 4.295 12.552 3.544
‐.243 .090 ‐.091 .069 .637 .100 .606 .098 ‐.319 .387 ‐.241 .319 ‐.565 .192 ‐.546 .178 ‐.531 .216 ‐.522 .186 ‐.021 .041 ‐.001 .039 ‐.020 .043 ‐.032 .039 .012 .041 ‐.001 .038
FAI Constant 42.953 15.364 ‐20.378 18.425 .006 .023 .162 .022 .330 .029 .401 .034 ‐7.129 2.722 4.075 3.275 .021 .008 ‐.009 .009 ‐.082 .010 ‐.044 .014 ‐.135 .015 ‐.077 .020 ‐.005 .012 ‐.044 .015
50
Table 3: Regressions with Crude Oil Pricing
Data from 1995 – 2006
Data from 1995 ‐ 2008
Coefficient Standard Error Coefficient Standard ErrorPrice Constant 2.008 2.344 .679 1.881
.217 .143 .144 .102 ‐1.025 .238 ‐.789 .217 .079 .108 .293 .094 .195 .109 .125 .100 .877 .175 .808 .117 1.113 .241 .838 .197 .494 .198 .450 .181 .259 .108 .249 .099
Supply Constant 15.993 1.790 7.419 1.648 ‐1.212 .157 ‐.252 .106 ‐.019 .035 ‐.061 .044 .003 .109 .508 .104 ‐.953 .088 ‐.650 .095 .803 .178 1.607 .171 .474 .074 .317 .086
Feed Constant ‐9.450 3.661 ‐2.397 1.654
‐.407 .087 ‐.234 .063 .227 .060 .152 .061 .046 .163 .300 .191 .294 .190 .598 .183 1.096 .340 ‐.051 .030 .877 .026 .910 .029 .575 .034 .539 .033 .301 .029 .269 .028
51
Exports Constant 13.634 4.302 12.783 3.627 ‐.252 .090 ‐.130 .070 .634 .100 .610 .100 ‐.322 .387 ‐.186 .327 ‐.578 .192 ‐.616 .181 ‐.541 .217 ‐.568 .192 ‐.022 .041 ‐.004 .038 ‐.020 .009 ‐.031 .039 .012 .041 0 .038
FAI Constant 40.094 17.803 ‐25.264 19.900 .006 .023 .158 .022 .333 .030 .404 .034 ‐6.623 3.153 4.939 3.536 .020 .009 ‐.012 .010 ‐.081 .011 ‐.042 .014 ‐.132 .017 ‐.072 .021 ‐.007 .013 ‐.046 .015 .005 .013 .013 .017