Monday, November 05, 2007

The Ethanol Bubble?



The New York Times reports that in less than one year, ethanol prices have plummeted over 30%. As a result, there is even talk of a government bailout for ethanol producers in case the price of ethanol falls too low!

So, why did price spikes in last year's ethanol market give way to falling prices this year? To understand the price fluctuations, we need to know how the short-run behavior of firms in competitive industries (such as ethanol) differs from their long-run behavior. In the textbook model of perfectly competitive industries, an increase in demand causes the equilibrium price of ethanol to increase in the short run—from P1 to P2 in the diagram below. In the short run, higher ethanol prices lead to higher profits for ethanol producers.

In the long run, the lure of profits attracts new ethanol producers. The long-run entry of additional ethanol producers expands the supply of ethanol, causing the price to fall back to its initial level:

Notice that economic profits converge to zero in the long run. As explained by most textbooks, zero economic profit does not mean that ethanol producers barely have enough to eat. Zero economic profit means that ethanol producers are earning incomes that compensate them for the next best salary they had to give up to go into producing ethanol.

Ultimately, in competitive environments, a surge in demand causes an initial spike in prices, but the equilibrium price gradually falls back toward initial levels. In the end, the long-run price of ethanol may not even change, but more ethanol will be produced than before.

Discussion Questions

1. Referring to the diagram on the left above, why does it take only a short period for prices to spike, but a long period for prices to fall again?

2. Referring to the diagram on the right above, why is the quantity of ethanol fixed for a period in the very short run?

3. Corn is a key ingredient to the production of ethanol. The New York Times article points out that corn prices have remained high over the past year even as the price of ethanol has declined. How might developments in the ethanol market have contributed to the rising price of corn?

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Monday, February 12, 2007

Fueling Protests and Cars



Tortillas—a central component of the Mexican diet—have been a source of recent uproar in Mexico. Rising tortilla prices fueled protests in Mexico City two weeks ago. Many people in Mexico earn only $5 per day, and with the price of tortillas approaching $0.45 per pound, protests were inevitable.

Tortilla prices may be fueling the protests, but it's the growing demand for corn among American ethanol producers that's fueling the rise in tortilla prices. As more and more ethanol plants come online in the U.S., the number of buyers in the corn market increases, putting upward pressure on corn prices. Rising corn prices mean rising input prices for tortilla makers and rising tortilla prices for consumers. So does fueling your Honda Accord with ethanol-laced gasoline take tortillas off the plates of Mexicans? The answer depends on the time horizon: the short run or the long run.

Three characteristics in the market for corn make it highly competitive. First, there are many corn producers in the United States, Mexico, and the rest of the world. Second, corn tastes about the same no matter which farmer sells you the corn. Third, there are few barriers to new corn producers entering the market in the long run.

In the short run, however, firms cannot exit or enter the market. Rising ethanol production in the U.S. creates a higher demand for corn. The market demand for corn shifts to the right from D1 to D2, increasing the price of corn from P1 to P2. Corn producers react to the higher price by producing more corn (moving from q1 to q2). The higher demand for corn also causes corn producers to earn an economic profit.

How does this affect the tortilla market in Mexico? Corn is a major input for tortillas—as corn prices rise, the cost of tortilla production rises. The supply of tortillas shifts to the left from S* to S**. The price of tortillas increases and the quantity of tortillas consumed decreases. The reduction in tortilla supply causes the price of tortillas to rise sharply in Mexico because tortillas are essential to the Mexican diet (the demand for tortillas is fairly inelastic). As a result, the financial burden of higher corn prices falls on tortilla consumers more so than the producers.

Fortunately, as the Los Angeles Times reports, help is on the way for the people of Mexico. In the long run, firms may exit or enter the market. Unusually high short-run profits in the corn market will undoubtedly cause more farmers to plant corn in the long run. As they do, the supply of corn will shift to the right from S1 to S2. As more farmers plant corn in the long run, profits return to normal and the price of corn falls. In the long run, as the diagrams suggest, it's possible that the higher demand for ethanol will have no effect on corn and tortilla prices.


Click here for another Aplia perspective on food prices and ethanol.

Discussion Questions

1. How would a price ceiling at P* affect the Mexican tortilla market?

2. Should the Mexican government subsidize tortilla producers until corn prices fall back to previous levels? How would a subsidy—or voucher—for tortilla consumers affect the tortilla market in the short-run?

3. Are Mexicans worse off or better off due to the increase in U.S. ethanol production?

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Wednesday, October 25, 2006

Slicker than Oil: The Debate Over California’s Proposition 87



Proposition 87, a hotly contested measure on the ballot in California, nicely illustrates the key lessons about tax incidence--who actually pays a tax. The political debate about this Proposition shows that these lessons, which are typically covered in an introductory microeconomics course, are not well understood by the voting public. Is education powerful or what? Armed with knowledge of just a few economic principles, you will be able to analyze important policy issues better than most.

To raise funds for research on and development of alternative fuels, Proposition 87 taxes oil produced in California. (Read a summary of the provisions of this act on the Secretary of State's web site.) Opponents of the tax claim that this tax will increase the price of gasoline at the pump. The following figure shows why this claim is wrong. The market for oil is global, and the price of oil is set by global supply and global demand. California produces less than 1% of all the oil produced in the world, so changes of a few percent in its output would be far too small to have a noticeable effect on global supply and demand. Taken together, all the producers in California are in the same position as a single firm in a competitive industry. They face a residual demand curve for their oil that is horizontal, or perfectly elastic, at a price equal to the world price of oil plus the cost of transporting it to California. Call this price P*.
To understand why the demand curve faced by local producers is horizontal, consider the decisions made by the typical manager of a gasoline refinery. She already has barrels of imported oil delivered to her at the price P* and could order many more at that same price. If the price of oil delivered from a local producer was more than P*, she wouldn't buy any. If it was less, she'd buy as much as she could and cut back on purchases of oil brought into the state from Alaska and the rest of the world. Local producers, understanding this, would be foolish to charge a price less than P*. They'd be leaving money on the table. Even if they did, this wouldn't reduce the price that the refinery manager would charge for gasoline. She'd happily buy all the cheap local oil she could, but still charge the same price for gasoline that other refiners, who continue to import foreign oil, are charging--the price determined by P* and the cost of refining.

What happens if the state of California imposes a tax of T% on the oil produced by the local producers? The figure shows that the price of oil purchased by the refineries is still equal to P*. Local producers receive (1 - T) times P* per barrel of oil. Because they face a horizontal demand curve, they bear the full cost of the tax. They can't pass the tax increase on to consumers.

As the figure shows, local production of oil will fall by a small amount after the tax is imposed, which means that imports of oil will go up. The amount of this reduction depends on the elasticity of the supply curve. As usual, the supply response grows larger over time. Initially, there should be very little supply response, but over time, wells will be retired from service sooner and fewer new wells will be drilled.

What might the size of this impact be? One estimate cited by opponents of Proposition 87 is that local production will fall by an average of about 3.4% or about 22,000 barrels per day over the first 10 years of the life of the tax. Oil produced in California meets only 37% of consumption there. The balance is supplied by oil imported to California from Alaska and the rest of the world. This means that imports of oil into the state would increase by about 1.8%. A gradual increase in imports of this magnitude would be too small to have any perceptible effect on the world price of oil or the transportation costs of oil to California.

The local producers do understand the economics of tax incidence. Chris Hall, an oil producer based in Torrance, CA, was quoted in the San Diego Union-Tribune as saying of the tax that “I can't pass it on…I'm a price taker and not a price maker. I don't determine the market.” Understandably, these producers have raised a lot of funds to support a campaign to oppose the imposition of this new tax. The tax would raise up to $4 billion before it expires, so for oil producers as a group, it makes sense to spend millions of dollars to defeat the tax. What is interesting about the campaign ads that they support is their repeated claim that the tax will raise the price of gasoline. No doubt, their campaign consultants have found that raising this irrelevant issue is the most effective way to get people to vote against this proposition.

Reasonable people can differ about whether Proposition 87 is a good idea. See the web page, by one well-known economist who studies energy, Severin Borenstein, for an even-handed discussion of its plusses and minuses. Or read this critique by Greg Mankiw. Ironically, he is opposed to the proposed tax because it will not increase gasoline prices and therefore will not encourage conservation. This kind of discussion clarifies the issues and helps people understand the underlying economic principles.

The other kind of political discussion, the kind that goes on between battling pundits or in the back and forth of campaign ads, sways some voters because they don't have the benefit of an introductory course in economics. They don't understand something that you do: a tax on a small subset of firms in a competitive industry will not affect the price paid by consumers.

1. Greg Mankiw correctly points out that the tax in Prop 87 is not a Pigovian tax--that is, a tax on oil for the purpose of reducing oil consumption to socially optimal levels. However, the revenues from Prop 87 are intended to subsidize the research and development of alternative energy. Because the marginal private benefit of R&D is less than the marginal social benefit, the market does not allocate enough resources to R&D on alternative fuels. Appropriate government subsidies could encourage a socially optimal level of R&D. Does this mean Prop 87 is in fact a Pigovian subsidy? Should Mankiw and the other members of his Pigou Club support such a policy? (Thomas Friedman and Al Gore, both of whom Mankiw counts among the membership of the Pigou club, already do. Other members of the Pigou club are encouraged to comment…)

2. Would a Pigovian tax on gasoline consumption be a better way to fund research on and development of alternative fuels? Why or why not?

3. How useful is it to enact public policy through ballot measures? On the one hand, polls show that the public isn’t well informed as to the economic consequences of Prop 87 and other ballot measures. On the other hand, the policies developed by legislators are also imperfect. Some people argue that elected officials face few political incentives to tackle long-term problems like global warming. Is Prop 87 an example of “direct democracy” achieving something the legislative process could not? Or is it an example of why setting public policy is best left up to the legislature?

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