Elasticity

Updated September 4, 2020

What Is Elasticity in Economics?

Elasticity is a measure of the change in one variable in response to a change in another. In economics, elasticity generally refers to variables such as supply, demand, income, and price. The degree of responsiveness to these changes helps identify and analyze causal relationships between variables. It is often expressed as a ratio or percentage.

Who Uses Elasticity?

Elasticity has a wide variety of applications in both economics and finance:

Policymakers: Analyze the impact that policies involving taxation, minimum wage, subsidies, etc. have on consumer behavior.
Businesses: Determine the effects a change in price may have on revenue.
Analysts: Measure trends such as the effects a change in income could have on consumer behavior.
Unions: If labor is a major input of a good, unions can use the elasticity of demand of that good to negotiate wages.
Entrepreneurs: Determine if a market is worth entering or if a product is worth selling.

Elastic vs. Inelastic Goods

The elasticity of goods measures sensitivity to price changes. Given a percentage change in price, an elastic good will have a greater percentage change in quantity supplied or demanded. On the other hand, an inelastic good will have a smaller percentage change in quantity demanded or supplied. This indicates that elastic goods are more sensitive to changes in price while inelastic goods are less sensitive.

5 Examples of Elastic Goods

Examples of elastic and inelastic goods

Elastic goods are goods which have a significant change in demand or supply in response to a change in price. Generally, these are goods that are not considered necessities, or goods for which there are substitutes readily available. Using demand as an example, if the price of a good were to decrease by X amount, there would be a greater increase in the amount that people would want to buy. If the price were to increase by X amount, there would be a greater decrease in the amount that people would want to buy.

1. Soft drinks

Soft drinks are not a necessity, so a big increase in price would cause people to stop buying or look for other brands. A big decrease in price, however, would be sure to attract more buyers.

2. Cereal

Like soft drinks, cereal is not a necessity and there are many different choices. A change in price would have a big impact on the demand.

3. Clothing

Similar to the above two examples, any particular item of clothing is not a necessity. Since buyers have a massive number of options, demand is largely affected by price.

4. Electronics

Most electronics have multiple options at each price point. Adjustments to price will greatly influence the demand for an item.

5. Cars

While many people shop for specific cars, there are many makes and models. If the price of a car increases, people will consider similar models. On the other hand, if the price decreases, more people will be interested in buying that car.

5 Examples of Inelastic Goods

Inelastic goods are goods that do not have a significant change in demand or supply in response to a price change. In general, these are goods that are considered necessary or goods for which there are few substitutes. Using demand as an example, if the price of a good were to decrease by X amount, there would be a smaller increase in the amount that people would want to buy. If the price were to increase by X amount, there would be a smaller decrease in the amount that people would want to buy. 5 examples of inelastic goods include:

1. Life-Saving Medication

If a person requires a life-saving medication (e.g. insulin), they will need to buy it regardless of the price. Because of this, adjustments to price will have a small effect on the demand.

2. Gas

The vast majority of cars use gasoline for fuel, so people will continue to buy it regardless of the price. Otherwise, they won’t be able to get to work, run errands, etc.

3. Electricity

Electricity is an essential part of our lives, so changes in the price would not have much of an effect on the demand for it. People might use slightly less if the price increases, but most don’t have the option to stop using it or switch to an alternative source of power.

4. Cigarettes

Goods like cigarettes are inelastic because they are addictive. Because quitting is not always an option, people will continue to pay for them if the price increases.

5. Post-Secondary Education

Many careers require a post-secondary degree or certification that cannot be obtained outside of colleges and universities. Because of this, increases in price will have little effect on the demand for post-secondary education. On the other hand, decreases in price would not have a major effect on demand because most people only pursue one degree or certification.

Elasticity Formula

The formula for elasticity is:

The elasticity formula

Value of Elasticity Coefficient

The value obtained from the above equation is called the elasticity coefficient, which measures the responsiveness of variable A to changes in variable B. The following table explains what the elasticity coefficient means:

ValueElasticityMeaning
Perfectly elasticAn increase in variable B causes variable A to drop to zero, a decrease in variable B causes variable A to go to infinity
>1Relatively elastic% Change in variable A is greater than the change in variable B
$1Unitary elastic% Change in variable A is the same as the change in variable B
<1Relatively inelastic% Change in variable A is less than the change in variable B
$0Perfectly inelasticVariable A is unaffected by changes in variable B

Types of Elasticity

There are four types of elasticity.  Each are used to explain the relationship between two economic variables: 

  • price elasticity of demand
  • price elasticity of supply
  • cross elasticity of demand
  • income elasticity of demand.

Price Elasticity of Demand (PED)

Price elasticity of demand is a measure of the change in demand for a good in response to a change in its price.

Price Elasticity of Demand Formula

The formula for price elasticity of demand is:

Price elasticity of demand formula

Price Elasticity of Supply (PES)

Price elasticity of supply is a measure of the change in supply of a good in response to a change in its price.

Price Elasticity of Supply Formula

The formula for price elasticity of supply is:

Price elasticity of supply formula

Cross Elasticity of Demand (XED)

Cross elasticity of demand is a measure of the change in demand for a good (in response to a change in the price of another good).

Cross Elasticity of Demand Formula

The formula for cross elasticity of demand is:

Cross elasticity of demand formula

Income Elasticity of Demand (YED)

Income elasticity of demand is a measure of the change in demand for a good (in response to a change in the buyer’s income).

The formula for income elasticity of demand is:

Income elasticity of demand formula

Ask An Expert

InvestingAnswers is on a mission to help consumers build and protect their wealth through education. That is why we have experts answering your pertinent questions at the end of each article.

Can Elasticity Be Negative?

Yes, in fact, most price elasticity of demand is negative. This reflects the inverse relationship between price and demand for most goods, that is, as price increases (decreases), the quantity demanded decreases (increases) . For some goods, income elasticity and cross elasticity of demand can also be negative.

Who Invented elasticity?

The concept of elasticity was published by economist Alfred Marshall in 1890.

What Is the Elasticity Coefficient?

The elasticity coefficient is the value found by solving the elasticity equation. This number tells us whether a variable is perfectly elastic, relatively elastic, unitary elastic, relatively inelastic, or perfectly inelastic.