1. Principles of Marketing
Elasticity
Microeconomics
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What is Marketing?
Principles of Marketing

2. Elasticity
How responsive or sensitive one thing is to a change in another thing
Mr. Fantastic. Authored by: Javi M. Located BY-SA: Attribution-ShareAlike

3. Factors that Affect Elasticity
Coffee Genie. Authored by: Matthew Wicks. Located at:  BY-NC: Attribution-NonCommercial

4. Substitutes
Price elasticity of demand is fundamentally about substitutes. If it’s easy to find a substitute product when the price of a product increases, the demand will be more elastic. If there are few or no alternatives, demand will be less elastic.

5. Necessities vs. Luxuries
A necessity is something you absolutely must have, almost regardless of the price. A luxury is something that would be nice to have, but it’s not absolutely necessary.  In general, the greater the necessity of the product, the less elastic, or more inelastic, the demand will be, because substitutes are limited. The more luxurious the product is, the more elastic demand will be.

6. Share of the Consumer’s Budget
If a product takes up a large share of a consumer’s budget, even a small percentage increase in price may make it prohibitively expensive to many buyers. The larger the share of an item in one’s budget, the more price elastic demand is likely to be.

7. Short Run Versus Long Run
Price elasticity of demand is usually lower in the short run, before consumers have much time to react, than in the long run, when they have greater opportunity to find substitute goods. Thus, demand is more price elastic in the long run than in the short run

8. Competitive Dynamics
Goods that can only be produced by one supplier generally have inelastic demand, while products that exist in a competitive marketplace have elastic demand. This is because a competitive marketplace offers more options for the buyer.

9. Practice Question: How elastic is the demand for:
Blood pressure medicine
Diamond engagement rings
Blood pressure medicine is very necessary and thus fairly inelastic. Patents and the time needed for drug development restrict competition.
Diamonds are generally a luxury, and they are a large share of a budget in the year they are purchased. Many other materials can be made into rings. The idea of a diamond engagement is culturally established and to some degree, diamond engagement rings signal wealth. People who value the tradition might buy smaller rings or wait a few more months to get engaged. Others might be more open to engagement puppies or watches or even rings with other materials.

10. Calculating Growth or Change
Percentage change= 𝐶ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝑞𝑢𝑎𝑛𝑡𝑖𝑡𝑦 𝑄𝑢𝑎𝑛𝑡𝑖𝑡𝑦
Gordon Robertson. Authored by: Wood Grain. Located at:  BY: Attribution

11. Calculating Price Elasticity of Demand
The price elasticity of demand is defined as the percentage change in quantity demanded divided by the percentage change in price:
Price elasticity of demand= 𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑐ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝑞𝑢𝑎𝑛𝑡𝑖𝑡𝑦 𝑑𝑒𝑚𝑎𝑛𝑑𝑒𝑑 𝑃𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 𝑐ℎ𝑎𝑛𝑔𝑒 𝑖𝑛 𝑝𝑟𝑖𝑐𝑒
There are two general methods for calculating elasticities:
The point approach uses the initial price and initial quantity to measure percent change
The more accurate approach is the midpoint approach, which uses the average price and average quantity over the price and quantity change

12. Price Elasticity of Demand
Principles of Microeconomics Chapter 5.1. Authored by: OpenStax College. Provided by: Rice University. Located BY: Attribution. License Terms: Download for free at
The price elasticity of demand is calculated as the percentage change in quantity divided by the percentage change in price

13. Price Elasticity of Supply
Principles of Microeconomics Chapter 5.1. Authored by: OpenStax College. Provided by: Rice University. Located BY: Attribution. License Terms: Download for free at
The price elasticity of supply is calculated as the percentage change in quantity divided by the percentage change in price.

14. Elasticity Is Not Slope
It’s a common mistake to confuse the slope of either the supply or demand curve with its elasticity. The slope is the rate of change in units along the curve, or the rise/run (change in y over the change in x)

15. Elasticity Changes Along the Demand Curve
Principles of Microeconomics Chapter 5.1. Authored by: OpenStax College. Provided by: Rice University. Located BY: Attribution. License Terms: Download for free at

16. Three Categories of Elasticity
If ...
Then ...
Called …
% change in quantity > % change in price
% change in quantity % change in price > 1
Elastic
% change in quantity = % change in price
% change in quantity % change in price = 1
Unitary
% change in quantity < % change in price
% change in quantity % change in price < 1
Inelastic
Principles of Microeconomics Chapter 5.1. Authored by: OpenStax College. Provided by: Rice University. Located BY: Attribution. License Terms: Download for free at

17. Perfect Elasticity or Infinite Elasticity
Principles of Microeconomics Chapter 5.2. Authored by: OpenStax College. Provided by: Rice University. Located BY: Attribution. License Terms: Download for free at

18. Perfect Inelasticity or Zero Elasticity
Principles of Microeconomics Chapter 5.2. Authored by: OpenStax College. Provided by: Rice University. Located BY: Attribution. License Terms: Download for free at

19. Income Elasticity of Demand
For most products, most of the time, the income elasticity of demand is positive: that is, a rise in income will cause an increase in the quantity demanded. This pattern is common enough that these goods are referred to as normal goods. However, for a few goods, an increase in income means that one might purchase less of the good; for example, those with a higher income might buy fewer hamburgers, because they are buying more steak instead. When the income elasticity of demand is negative, the good is called an inferior good

20. Cross-Price Elasticity of Demand
A change in the price of one good can shift the quantity demanded for another good.
For complements, like bread and peanut butter, then a drop in the price of one good will lead to an increase in the quantity demanded of the other good
if the two goods are substitutes, like plane tickets and train tickets, then a drop in the price of one good will cause people to substitute toward that good, and to reduce consumption of the other good

21. Wage Elasticity of Labor Supply
In the labor market, for example, the wage elasticity of labor supply—that is, the percentage change in hours worked divided by the percentage change in wages—will determine the shape of the labor supply curve
In general wage elasticity of labor supply depends on age

22. Elasticity of Savings
In markets for financial capital, the elasticity of savings—that is, the percentage change in the quantity of savings divided by the percentage change in interest rates—will describe the shape of the supply curve for financial capital
In the short run, the elasticity of savings with respect to the interest rate appears fairly inelastic

23. Formulas for Calculating Elasticity
Elasticity Type
Formula
Income elasticity of demand
=%change in Qd / % change in income
Cross-price elasticity of demand
=% change in Qd of good A / % change in price of good B
Wage elasticity of labor supply
=% change in quantity of labor supplied / % change in wage
Wage elasticity of labor demand
=% change in quantity of labor demanded / % change in wage
Interest rate elasticity of savings
=% change in quantity of savings / % change in interest rate
Interest rate elasticity of borrowing
=% change in quantity of borrowing / % change in interest rate
Principles of Microeconomics Chapter 5.4. Authored by: OpenStax College. Provided by: Rice University. Located BY: Attribution. License Terms: Download for free at

24. Total Revenue
The key consideration when thinking about maximizing revenue is the price elasticity of demand. Total revenue is the price of an item multiplied by the number of units sold: TR = P x Qd
Elasticity and Price Changes. Provided by: Lumen Learning. Located at:  BY: Attribution
Principles of Microeconomics Chapter 5.3. Authored by: OpenStax College. Provided by: Rice University. Located BY: Attribution. License Terms: Download for free at

25. Impact of a Price Change on Revenue
Change in Qd
Impact on Revenue
Elastic demand
% change in Qd is greater than % change in P
A given % rise in P will be more than offset by a larger % fall in Q so that total revenue (P times Q) falls.
Unitary demand
% change in Qd is equal to % change in P
A given % rise in P will be exactly offset by an equal % fall in Q so that total revenue (P times Q) is unchanged.
Inelastic demand
% change in Qd is less than % change in P
A given % rise in P will cause a smaller % fall in Q so that total revenue (P times Q) rises.
Reading: Elasticity and Total Revenue. Provided by: Lumen Learning. License: CC BY: Attribution

26. When do Firms Pass Cost-Savings to Customers?
When demand is inelastic.
Principles of Macroeconomics Chapter 5.3. Authored by: OpenStax College. Located BY: Attribution. License Terms: Download for free at

27. When do Firms Pass Higher Costs onto Consumers?
When demand is inelastic.
Principles of Macroeconomics Chapter 5.3. Authored by: OpenStax College. Located BY: Attribution. License Terms: Download for free at

28. Shifts in Supply
The shift in supply can result either in a new equilibrium with a much higher price and an only slightly smaller quantity, as in (a), or in a new equilibrium with only a small increase in price and a relatively larger reduction in quantity, as in (b). Often a represents the short term impact while b represents the longer term impact.
Principles of Macroeconomics Chapter 5.3. Authored by: OpenStax College. Located BY: Attribution. License Terms: Download for free at

29. Quick Review What is elasticity?
What are the price elasticity of demand and price elasticity of supply? How are they calculated using the midpoint method?
What are other elasticities using common economic variables? How are they calculated?
How does a firm’s price elasticity of demand affect total revenue?