Elasticity of Supply: Meaning and Importance
The law of supply explains the general relationship between the price of a commodity and the quantity supplied, but it doesn’t provide specific details about how much supply changes when the price changes. To understand this more clearly, we need to look at the concept of elasticity of supply. In this article, we will discuss key ideas related to the elasticity of supply, the elasticity of the supply formula, different types of elasticity of supply, the supply curve characteristics, how to measure its price elasticity and many more.
What is Elasticity of Supply?
The price elasticity of supply measures how much the quantity supplied changes when the price of a product changes. It helps understand how the supply of a product is affected by price fluctuations in the market. It also provides an idea of the profit that can be earned by selling the product at different prices. Price elasticity of supply refers to how the supply of a good or service reacts to a change in its price. According to basic economic theory, when the price of a product increases, the supply of that product usually decreases.
Similarly, the price elasticity of demand can be studied to understand how demand for a product changes with price changes. If the price of a product changes, the demand for that product changes quickly. This is called price elasticity of demand.
Elasticity of Supply Example
Imagine the price of coffee rises from $3 to $4 per cup. If coffee producers can quickly increase the amount of coffee they produce to meet the higher demand, the supply is considered elastic. This means that producers are able to respond to the price change by supplying more coffee.
On the other hand, if the price of housing rises, but builders cannot quickly construct more houses due to limited land, time, and resources, the supply of houses is considered inelastic. The quantity of houses supplied doesn't change much in response to price increases.
In summary, the elasticity of supply shows how much producers can adjust the quantity they supply when prices change.
Price Elasticity of Supply Formula
After having understood the elasticity of supply definition in economics, we now move to the elasticity of supply formula which is based on its definition.
\[E_{S} = \dfrac{\% \Delta P}{\% \Delta Q}\]
Here, \[E_{S}\] denotes the elasticity of supply which is equal to the percentage change in quantity supplied divided by the percentage change in the price of the commodity.
The Law of Supply
In a free market, producers compete to make profits, so profits are never the same over time or for different products. Because of this, entrepreneurs move resources and labour to products that make more money and away from those that make less money.
The law of supply explains that price and quantity are connected. For example, if consumers want more oranges and fewer apples, more money will be spent on oranges, while less will be spent on apples. As a result, the price of oranges goes up.
Steps to Measure Elasticity of Supply:
Calculate the change in quantity supplied: Find the difference in the quantity supplied before and after the price change.
Calculate the change in price: Find the difference in the price before and after the change.
Use the formula: Apply the changes in quantity supplied and price to the formula.
5 Types of Elasticity of Supply
The price elasticity of supply has five types: perfectly elastic, more than unit elastic, unit elastic supply, less than unit elastic, and perfectly inelastic. Read below to learn more about each type in detail.
Perfectly Elastic Supply: A commodity becomes perfectly elastic when its elasticity of supply is infinite. This means that even for a slight increase in price, the supply becomes infinite. For a perfectly elastic supply, the percentage change in the price is zero for any change in the quantity supplied.
More than Unit Elastic Supply: When the percentage change in the supply is greater than the percentage change in price, then the commodity has the price elasticity of supply greater than 1.
Unit Elastic Supply: A product is said to have a unit elastic supply when the change in its quantity supplied is proportionate or equal to the change in its price. The elasticity of supply, in this case, is equal to 1.
Less than Unit Elastic Supply: When the supply of a product changes less than its price, we can say that the supply is relatively inelastic. In this situation, the price elasticity of supply is less than 1.
Perfectly Inelastic Supply: Product supply is said to be perfectly inelastic when the percentage change in the quantity supplied is zero irrespective of the change in its price. This type of price elasticity of supply applies to exclusive items. For example, a designer gown styled by a famous personality.
It is important to note that the elasticity of supply is always a positive number. This is because the law of supply says that the quantity supplied is always directly related to changes in the price of a product. In other words, when the market price of a product increases, its supply either increases or stays the same.
Determinants of Elasticity of Supply
Marginal Cost- As the cost of producing one more unit is rising with output or Marginal Costs (which are the increased costs related to each additional unit produced) are rising rapidly with output, then the rate of output production will be limited, i.e Price Elasticity of Supply will be inelastic., which means that the percentage of quantity supplied changes less than the change in price. However, if Marginal Cost rises slowly, then Supply will be elastic.
Time- As supply's price elasticity rises over time, producers would boost the quantity supplied by a larger percentage compared to the increase in price.
Number of Firms- It is more likely that the supply will be elastic when there are a large number of firms. This occurs because other firms can step in to fill the supply gap.
Mobility of Factors of Production- When the factors of production can move easily, the price elasticities of supply become higher. This means that labour and other resources needed for production can be brought in from different areas to boost production quickly.
The Elasticity of Supply Curves
We have previously inferred the elasticity of supply definition, the elasticity of supply formula, and its various types. Let us now have a look at how these different values of the price elasticity of the supply formula are plotted on the graph.
Keeping the quantity supplied on the X-axis and the price of the commodity on the Y-axis, we can draw certain conclusions from the different values of elasticity of the supplied formula.
When \[E_{S}\] = infinite (Perfectly elastic supply), the curve (SS) is a straight line parallel to the X-axis.
When \[E_{S} > 1\], a flatter curve (\[S_{2}S_{2}\]) is obtained which when extended intersects the Y-axis.
When \[E_{S} < 1\], it results in a steeper curve (\[S_{3}S_{3}\]), which when extended crosses the X-axis.
When \[E_{S} = 1\], the curve (\[S_{4}S_{4}\]) comes out to be a straight line that passes through the origin at an angle of 45 degrees.
When \[E_{S} = 0\] (Perfectly inelastic supply), the curve (\[S_{1}S_{1}\]) obtained is parallel to the Y-axis.
This graph shows us the relationship between the different types of elasticity of supply and helps in understanding the elasticity of supply definition better.
Did You Know?
Alfred Marshall, a British economist, gave the concept of elasticity of demand and supply in his book “Principles of Economics” in 1890. He was the one to define the elasticity of supply and deduced the price elasticity of the supply formula. He also explained that the prices of some goods such as medications, salt, gasoline, etc. can increase without reducing their demand in the market, which means that their prices are inelastic. This is because these goods are crucial to the everyday lives of consumers.
Conclusion
The elasticity of supply is a key concept that helps us understand how producers respond to price changes. It shows the relationship between price and the quantity of a product supplied. The greater the ability of producers to adjust production when prices change, the more elastic the supply. On the other hand, when producers are less able to adjust supply in response to price changes, the supply is considered inelastic.
By measuring the price elasticity of supply, businesses and economists can predict how changes in prices might affect supply in various industries. Understanding this concept is essential for pricing strategies, production planning, and understanding market dynamics. Ultimately, the elasticity of supply plays a significant role in determining how efficiently markets operate in response to changing economic conditions.
FAQs on Elasticity of Supply
1. What is meant by the price elasticity of supply in economics?
Price elasticity of supply (Es) is a measure used in economics to show how responsive the quantity supplied of a good or service is to a change in its price. It quantifies the Law of Supply by calculating the percentage change in quantity supplied for a one percent change in price, helping to understand how quickly producers can react to market price changes.
2. How is the price elasticity of supply calculated using the percentage method as per the CBSE Class 11 syllabus for 2025-26?
According to the percentage method, the price elasticity of supply is calculated using the formula:
Es = (% Change in Quantity Supplied) / (% Change in Price)
Where the percentage change in quantity supplied is found by dividing the change in quantity by the original quantity, and the percentage change in price is found by dividing the change in price by the original price.
3. What are the five types or degrees of elasticity of supply?
The five degrees of price elasticity of supply are:
- Perfectly Elastic Supply (Es = ∞): An infinite quantity is supplied at a specific price, but none at all at a slightly lower price. The supply curve is a horizontal line.
- Relatively Elastic Supply (Es > 1): The percentage change in quantity supplied is greater than the percentage change in price.
- Unitary Elastic Supply (Es = 1): The percentage change in quantity supplied is exactly equal to the percentage change in price.
- Relatively Inelastic Supply (Es < 1): The percentage change in quantity supplied is less than the percentage change in price.
- Perfectly Inelastic Supply (Es = 0): The quantity supplied does not change at all, regardless of the price. The supply curve is a vertical line.
4. What is the difference between elastic and inelastic supply, with a real-world example?
The key difference lies in the degree of responsiveness to price changes.
- Elastic supply (Es > 1) means producers can significantly increase output when prices rise. For example, manufacturers of consumer goods like t-shirts can easily increase production by adding more shifts.
- Inelastic supply (Es < 1) means producers cannot easily change output when prices change. For example, the supply of beachfront properties is highly inelastic because the amount of land is fixed and new properties cannot be created quickly.
5. What are the key factors or determinants that influence the price elasticity of supply?
Several factors determine whether the supply of a good is elastic or inelastic:
- Time Period: Supply is more elastic in the long run as firms have more time to adjust production capacity.
- Nature of the Commodity: Durable goods (e.g., furniture) have more elastic supply than perishable goods (e.g., fresh vegetables).
- Production Technology: Advanced and flexible technology allows for a more elastic supply.
- Availability of Inputs: If factors of production are easily available, supply can be increased easily, making it more elastic.
- Marginal Cost of Production: If the cost of producing additional units rises sharply, supply will be more inelastic.
6. How does the geometric method represent different degrees of elasticity on a supply curve?
The starting point of a straight-line supply curve on the axes indicates its elasticity:
- A supply curve that originates from the Y-axis is elastic (Es > 1).
- A supply curve that originates from the X-axis is inelastic (Es < 1).
- A 45° supply curve that passes through the origin is unitary elastic (Es = 1).
- A horizontal supply curve parallel to the X-axis is perfectly elastic (Es = ∞).
- A vertical supply curve parallel to the Y-axis is perfectly inelastic (Es = 0).
7. Why is the value for price elasticity of supply always positive?
The value for price elasticity of supply is always positive because of the direct relationship between price and quantity supplied, as stated by the Law of Supply. When the price of a product increases, producers are incentivised to supply more to increase their profits. Since both price and quantity supplied move in the same direction (both increase or both decrease), the resulting elasticity coefficient is always a positive number.
8. How does the nature of a commodity, such as being perishable or durable, impact its supply elasticity?
The nature of a commodity significantly impacts its supply elasticity. Durable goods, like cars or appliances, have a relatively elastic supply because producers can store them in inventory. If prices rise, they can release stock, and if prices fall, they can hold it. In contrast, perishable goods, like fresh flowers or milk, have an inelastic supply as they cannot be stored for long and must be sold quickly, making it difficult for suppliers to adjust the quantity based on price changes.
9. What is the practical importance of understanding price elasticity of supply for a business?
Understanding price elasticity of supply is crucial for businesses for several reasons. It helps in making informed production decisions; a firm with an elastic supply can rapidly scale production to capitalize on high prices. It also influences pricing strategy and revenue forecasting. For industries with inelastic supply, like specialized mining, businesses know that output cannot be changed quickly, which affects long-term investment and planning.
