Archive for the 'Elasticity' Category

Sep 02 2011

How to have your pasta and eat it too – understanding the allocating function of prices in a market economy

Have a look at this article before reading the blog post below: Pasta prices rise after North Dakota loses million acres of wheat to heavy rain, flooding – Associated Press

Prices are determined by the relative scarcity of a good, service or productive resource. This fundamental lesson is one of the first things we learn in a high school economics class. Why are diamonds, which nobody really needs, so much more expensive than water, which everyone needs? The answer lies not in the relative demands for the two goods (clearly, water is far more demanded than diamonds), but rather the relationship between the relative demand and the supply. Between the two, diamonds are far more limited in supply than water, thus they are scarcer and accordingly more expensive.

This lesson applies not only to water and diamonds, but indeed to any product for which there is a market in which buyers and sellers engage in exchanges with one another. Commodities are goods for which there is a demand,  but for which the supply is standardized across all markets. For instance, bicycles are not a commodity, because there are hundreds of different types of bicycles, meaning it is not a standardized product. But steel, which is used to make bicycles, is a commodity since steel is fairly standard regardless of its ultimate use by manufacturers. Cookies are not a commodity, but wheat is, since wheat is a highly standardized ingredient used in the production of cookies.

Commodity prices, like the prices of anything, are determined in markets. Buyers are usually the manufactures of secondary products for which the commodities are an input. Since commodities are traded all over the world, there tends to be a common market price determined by the national or international supply and demand for the commodity. In recent weeks, one very important commodity has increased in scarcity, leading to an increase in the price for the finished product the commodity is used to produce.

Consumers are paying more for pasta after heavy spring rain and record flooding prevented planting on more than 1 million acres in one of the nation’s best durum wheat-growing areas.

North Dakota typically grows nearly three-fourths the nation’s durum, and its crop is prized for its golden color and high protein. Pasta makers say the semolina flour made from North Dakota durum produces noodles that are among the world’s best.

This year’s crop, however, is expected to be only about 24.6 million bushels, or about two-fifths of last year’s. Total U.S. production is pegged at 59 million bushels, a little more than half of last year’s and the least since 2006, according to the U.S. Department of Agriculture.

The cost of pasta jumped about 20 cents in the past few months to an average of about $1.48 a pound nationwide…

…North Dakota durum fetched about $15 a bushel this spring but has dropped to about $11, due to the lack of buying and selling.

Still, that’s about twice what it sold for at this time last year, she said…

“This is one of the few crops we have that can have such an immediate impact on the consumer,” Goehring said. “This year, they will experience higher pasta prices.”

The story above is one played out in countless markets for commodities (such as wheat) and the goods they are used to produce (pasta, in this case) all the time. Due to poor weather and a particularly wet spring, farmers were unable to plant as many of their fields with wheat as they have in the past. Therefore, the 2011 wheat harvest is less than it usually is, meaning the supply of wheat has decreased. However, since there has been no fundamental change to the demand for wheat (we still eat pasta!) the relative scarcity of wheat is greater than in the past. Demand remained constant, while supply fell, therefore the relative scarcity increased.

The value of anything is based on its relative scarcity. In product markets, like that for wheat, value is conveyed by the commodity’s price. As the article says, the price of wheat is currently selling at “about twice what it sold for at this time last year”. At the current price of $11 per bushel, we can assume that the price last year was $5.50. However, the price reached as high as $15 earlier in the summer, indicating that the reduced supply of 59 milliion bushels, which is “a little more than half of last years” (which we’ll assume was around 100 million bushels), caused the price to peak at $15 this year. All this is a complicated way of saying that as the output of wheat fell, wheat prices rose because demand remained constant.

Additionally, the price of the product for which wheat in an input also rose. Pasta prices have jumped “20 cents in the past few months” to $1.48. Since the price of wheat is a resource cost for pasta producers, higher wheat prices lead to a fall in the supply of pasta, making pasta more scarce and driving the price up for pasta consumers.

All this can be demonstrated graphically using simple supply and demand analysis.

Based on the figures in the graphs above, the responsiveness of wheat consumer (which are mostly pasta producers) to the rising price of wheat can be easily calculated. Price elasticity of demand (PED) is the measure of consumers’ sensitivity to price changes. It is measured by calculating the percentage change in quantity following a price change divided by the percentage change in price. The quantity demanded of wheat fell by 41%, while the price rose by 272%, meaning that the PED for wheat is 41/272, or 0.15. This is considered relatively inelastic since such a large price increase led to a relatively small fall in the quantity of wheat demanded.

It is likely that if wheat prices remain elevated throughout 2011, next spring farmers across the American Midwest will have a strong incentive to plant more acres of wheat than they have in years past. Assuming the weather conditions improve and the fields are dry enough to grow wheat, it would be expected that a year from now wheat prices will be much lower than they are today, as supply returns to or exceeds historical levels next year. High prices for wheat today have harmed pasta consumers, but in the long run everyone, both pasta producers and pasta consumers, will likely enjoy lower prices thanks to the high prices of today.

This is how the market system works. When resources are under-allocated towards a particular good, as they have been towards wheat in 2011, price rises in response to the good’s increased scarcity. But the higher prices incentivize producers to allocate more resources towards those goods’ production, and over time the supply increases once more, reducing its scarcity and bringing the price back down.

Discussion Questions:

  1. Why did wheat become more scarce in 2011, even though the demand for wheat did not change?
  2. Interpret the claim that “wheat consumers are relatively unresponsive to higher wheat prices”. Can you think of a reason why this is the case? Can you think of an example of a product for which consumers would likely be much more responsive to a change in the price?
  3. How does the high price of wheat and pasta in 2011 likely assure that a year from now, prices will be much lower than they are today, assuming there are not further problems with flooding in wheat growing areas?
  4. How do prices “allocate resources” in a market economy? What do you think would have happened to the number of acres farmers would plant in wheat next year if instead of the price doubling this summer, it had been half of what it was in previous years?

3 responses so far

Dec 01 2010

Elasticity Haikus

Published by under Elasticity,Humor

One particularly witty student submitted his Economics Learning Log for our Elasticities unit with the following thoughtful poems.

On Price Elasticity of Demand:

Price may increase fast

Inelastic good’s demand

Stays in place for good

On Cross-price Elasticity of Demand:

Vodka drinkers fear

Russians tax it, prices soar

I’ll drink beer instead

On Income Elasticity of Demand:

Wages cut in half

No more decadent lifestyle

I miss my Rolls Royce

On Price Elasticity of Supply:

Demand for sweets down

Asbestos found in lollipops

Guess I’ll make fewer

Well done, Nick! Keep the haikus coming!

16 responses so far

Nov 01 2010

The problem with price controls in Europe’s agricultural markets

The following is an excerpt from chapter three of my upcoming IB Economics Textbook published by Pearson Baccalaureate

Understanding price elasticity of supply, which measures the responsiveness of producers to changes in the price of different goods, allows firm managers and government policymakers to better evaluate the effects of their output decisions and economic policies.

Excises taxes and PES: A tax on a particular good, known as an excise tax, will be paid by both the producers and the consumers of that good. When a government taxes a good for which supply is highly elastic, it is the consumer who ends up bearing the greatest burden of the tax, as producers are forced to pass the tax onto buyers in the form of a higher sales price. If the producer of a highly elastic good bears the the tax burden itself, it may be forced to reduce output to such a degree that production of the good becomes no longer economically viable. A tax on a good for which supply is highly inelastic will be born primarily by the producer of the good. The price paid by consumers will only increase slightly while the after-tax amount received by the producer will decrease significantly, but in the case of inelastic supply this will have a relatively small impact on output. A graphical representation of the effects of taxes on different goods will be introduced in chapter 4.

Price controls and PES: A common policy in rich countries aimed at assisting farmers is the use of minimum prices for agricultural commodities. The European Union’s Common Agricultural Policy (CAP) involves a complex system of subsidies, import and export controls and price controls, the objective of which is to ensure a fair standard of living for Europe’s agricultural community. The use of minimum prices in agricultural markets can have the unintended consequence of creating substantial surpluses of unsold output. Take the example of butter in the EU. The following excerpt was taken from the January 22, 2009 issue of the New York Times:

“Two years after it was supposed to have gone away for good, Europe’s ‘butter mountain’ is back… Faced with a drastic drop in the [demand for] dairy goods, the European Union will buy 30,000 tons of unsold butter. Surpluses… have returned because of the sharp drop in the [demand for]… butter and milk resulting partly from the global slowdown.

In response, the union’s executive body, the European Commission, said it would buy 30,000 tons of butter at a price of 2,299 euros a ton… Michael Mann, spokesman for the European Commission, said that the move was temporary but that if necessary, the European Union would buy more than those quantities of butter — though not at the same price.”

The situation in the European Union butter market can be attributed to an underestimate by policy makers of the responsiveness of butter producers to the price controls established under the CAP. A minimum price scheme of any sort, if effective, will result in surplus output of the good in question, but the 30,000 tons of unsold butter in Europe appears to exceed the expected surplus considerably. The graph below illustrates why:

A price floor (Pf) is set above the equilibrium price of butter established by the free market. Butter producers in Europe are guaranteed a price of Pf, and any surplus not sold at this price will be bought by the European Commission (EC). Assuming a relatively inelastic supply, which corresponds with the short-run period (Ssr), the increase in butter production is relatively small (Qsr), resulting in a relatively small surplus (Qsr – Qd). In the short-run, the amount of surplus butter the EU governments needed to purchase was minimal. But as we learned earlier in this chapter, as producers of goods have time to adjust to the higher price, which in the case of the CAP is a price guaranteed by the EC, they become more responsive to the higher price and are able to increase their output by much more than in the short-run. Slr represents the supply of butter in Europe after years of the minimum price scheme. As demand has fallen due to the global economic slowdown, butter producers have continued to produce at a level corresponding with the price floor (Pf), leading to ever growing butter stocks and the need for the EC to spend, in this case, 69 million euros on surplus butter.

Understanding the behavior of producers in response to changes in prices, whether due to excise taxes or price controls, better allows both firm managers and government policy makers to respond appropriately to the conditions experienced by producers and consumer in the market place and avoid inefficiencies resulting from various economic policies.

Discussion questions:

  1. Explain why the price elasticities of both demand and supply of primary commodities tend to be relatively low in the short run and higher in the long-run.
  2. Explain the factors which influence price elasticity of supply. Illustrate your answer with reference to the market for a commodity or raw material.
  3. Discuss the importance of price elasticity of supply and price elasticity of demand for producers of primary commodities in less developed countries.

6 responses so far

Oct 24 2010

What does a good IB Economics Commentary look like?

It’s that time of the IB Economics course when I get to start teaching my year one students to write the dreaded Internal Assessment Commentaries. For their first IA, my students are writing a commentary on an article relating to Section 2.1 and 2.2 of the IB course, on supply, demand, market equilibrium and elasticities.

After reading a dozen or so out of my 38 students’ first drafts, I began to realize that what many of them needed was a clearer idea of what a good IB Economics commentary should look like. So I went back through past years’ commentaries and decided in the end just to write a sample commentary myself.

As you know, I do a lot of economics writing, so I thought this would be a breeze; I’d bust out a 700 word commentary modelling to my students what a top IA should look like. Well, I did it, but it proved to be much harder than I thought it would be. Why? Because after my first draft I was at 1100 words! The word limit, as IB students know, is 750, so I proceeded to spend as much time as it took me to write figuring out how to get it down to within the word limit.

Well, I did it. Below is my sample commentary for year one IB students. I do owe some credit to a past student of mine, Maren, whose article I stole and whose own commentary I adapted to write this one.

First, here’s the link to the article:

Where is Switzerland’s Cheapest Place to Live? – SwissInfo

And my commentary:

Introduction of theory:
Demand, supply and elasticity are basic economic concepts that when applied to different markets can help governments and individuals make informed decisions about things as basic as where to live and how to collect taxes.

Connection to article:
Recently, Credit Suisse conducted a survey and determined that Switzerland’s most expensive canton is Geneva, while the cheapest place to live is Appenzell Inner Rhodes, (AIR)

Analysis:
Demand is a curve showing the various amounts of a product consumers want and can purchase at different prices during a specific period of time. Supply is a curve showing the different amounts of a product suppliers are willing to provide at different prices. Equilibrium price and quantity are determined by the intersection of demand and supply. Price elasticity of demand (PED) indicates the responsiveness of consumers to a change in price, and is reflected in the relative slope of demand.

In the graph below, the markets for housing in Geneva and AIR are shown.

Demand for housing in Geneva (Dg), is high because of the many employment opportunities there. In addition, Geneva’s scarce land means supply of housing is low, resulting in a high equilibrium rent (Rg). Demand for housing in Geneva is inelastic, since renters in Geneva are less responsive to changes in rent compared to AIR, perhaps due to the perceived necessity of living close to their work.

Demand for housing in AIR (Da) is low, but supply is high due to the abundance of land. AIR is a rural canton with few jobs, therefore fewer people are willing and able to live there than in Geneva. Since living in the countryside is not a necessity, demand is relatively elastic, or responsive to changes in rent. The lower demand and greater supply make the AIR’s equilibrium rent relatively low.

The effect of a tax on property is a shift of the supply curve to the left and in increase in rents as landowners, forced to pay the canton a share of their rental incomes, raise the rent they charge residents.

In Geneva, property taxes are high, but this has little effect on the quantity demanded.

Geneva’s property tax shifts the supply of housing leftwards, as fewer landlords will be willing and able to supply properties to renters when the canton taxes rental incomes. However, the decrease in quantity demanded is proportionally smaller than the increase in the price caused by the tax, since demand for housing in Geneva is highly inelastic, or unresponsive to the higher price caused by the tax.

Renters in AIR are far more responsive to higher rents caused by property taxes, perhaps because living in AIR is not considered a necessity and there are more substitutes for rural cantons to live in. Renters in Geneva do not have the freedom to live in one of Switzerland’s many rural cantons, and are therefore less responsive to higher rents resulting from cantonal taxes.

Evaluation:
A tax decrease in AIR could lead to a significant increase in the number of people willing to live there, since renters are highly responsive to lower taxes. To some extent, housing in AIR and Geneva are substitutes for one another. Lower taxes in AIR would make living there more attractive, and subsequently the demand for housing in Geneva would fall putting downward pressure on rents there. People would move to AIR, attracted by lower rents, and commute to work in the cities. According to the article, this is already happening:

The disparity in the amount of disposable income… has increased the trend of people moving cantons for financial reasons… Economic necessities had led to an increase… of people moving address and opting to commute into work”.

There are many determinants of demand for housing in Switzerland, the primary one being location. High rents in Geneva are explained by the high demand for and the limited supply of housing. On the other hand, residents in AIR enjoy much lower rents, due to the weak demand and abundant land. Cantons should take into consideration the PED for housing when determining their property tax levels. Raising the tax Geneva will have little effect on rentals but could create substantial tax revenue. On the other hand, reducing taxes in AIR may attract many households away from the city to the countryside, drawn by the lower rents and property taxes.

Applying the basic principles of demand, supply and elasticity to Switzerland’s housing market allows households and government alike to make better decisions about where to live and how much to tax citizens.

Note: To see the full commentary including a cover page and highlighted article, click here

46 responses so far

Oct 05 2010

From heart transplants to watermelons: Understanding price elasticity of demand

Consumers are interesting creatures to study. Economics offers us a unique set of tools for understanding the behavior of consumers in various markets. Elasticity is one of those tools, one which helps us understand how consumers will respond to the change in price of some goods more or less than others. Some of the questions about consumer behavior elasticity helps answer are:

  • Why do governments place such huge taxes on cigarettes?
  • Why did Apple cut the price of the new iPhone in half from the original one, despite the fact that it had so many new features?
  • Why do movie theaters seem to raise their prices so steadily over the years, rather than doubling the price of tickets each year?

These and other questions can be answered by knowing something about the relative price elasticities of demand for the goods in question. Price elasticity of demand refers to the sensitivity of consumers to a change in price. For some goods, even the slightest increase in price will scare consumers away, while for others, price can go up and up and up and the quantity demanded won’t budge!

Here’s just one illustration of a good for which consumers are extremely sensitive to changes in price: Every autumn, around the city of Shanghai thousands of small farms harvest the Chinese watermelon, a small, green, juicy melon that looks and tastes the same regardless of which farm it came from. The farmers sell their melons to one of the hundreds of melon vendors who drive their big blue trucks into the city of Shanghai during about two weeks in October to sell the watermelons to the city folk who love their refreshing taste.

During the two weeks of the melon harvest, there are hundreds of blue trucks parked two or three per block all over the city. The hundreds of melon vendors sell an identical product, acquired at identical costs from thousands of farms using identical techniques for farming. In other words, the melon market in Shanghai during these two weeks is close to being perfectly competitive.

The price of melons is established through competition at something very close to the exact cost to the vendor of getting the melons into the city. Consumers know this, and therefore if one vendor tries to sell his melons for more than the equilibrium price, consumers will respond by buying NONE of that vendors melons. Conversely, if a vendor were to lower his price at all, rationally EVERY consumer would want to buy from that vendor, but since the price is already at the cost to the vendor, no vendor is able to lower the price without losing money. The outcome in the market for melons in Shanghai is that demand for melons is close to being perfectly elastic, meaning that consumers are completely sensitive to changes in price of watermelons.

Not all goods are like watermelons. In fact, for some goods demand is close to perfectly inelastic. Study the graph below, showing the relative elasticities of five different products, then answer the questions below in your comment!

Discussion Questions:

  1. For which product is demand pefectly inelastic? Perfectly elastic? Unit elastic?
  2. What relationship exists between relative slopes of demand curves and elasticity?
  3. What are two characteristics of cigarettes that make demand for them inelastic?
  4. What are two characteristics of heart transplants that make demand perfectly inelastic?
  5. What are the characteristics of a good for which demand is perfectly elastic?

93 responses so far

« Prev - Next »