What is Elasticity of Demand?

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Grade Level:

Class 12

AI/ML, Physics, Biotechnology, FinTech, EVs, Space Technology, Climate Science, Blockchain, Medicine, Engineering, Law, Economics

Definition

What is it?

Elasticity of Demand measures how much the demand for a product changes when its price changes. It tells us if customers are very sensitive to price changes or not. If demand changes a lot, it's 'elastic'; if it changes little, it's 'inelastic'.

Simple Example

Quick Example

Imagine the price of your favourite samosa shop increases from Rs 10 to Rs 12. If suddenly very few people buy samosas, then the demand for samosas is elastic. But if almost everyone still buys samosas, then the demand is inelastic.

Worked Example

Step-by-Step

Let's calculate the Elasticity of Demand for mobile data.

Step 1: Initial Price (P1) = Rs 300 for 1 GB. Initial Quantity Demanded (Q1) = 1000 GB.
---Step 2: New Price (P2) = Rs 360 for 1 GB. New Quantity Demanded (Q2) = 800 GB.
---Step 3: Calculate Percentage Change in Quantity Demanded: ((Q2 - Q1) / Q1) * 100 = ((800 - 1000) / 1000) * 100 = (-200 / 1000) * 100 = -20%.
---Step 4: Calculate Percentage Change in Price: ((P2 - P1) / P1) * 100 = ((360 - 300) / 300) * 100 = (60 / 300) * 100 = 20%.
---Step 5: Apply the formula: Elasticity of Demand = Percentage Change in Quantity Demanded / Percentage Change in Price.
---Step 6: Elasticity of Demand = -20% / 20% = -1.
---Step 7: We usually take the absolute value, so Elasticity of Demand = 1.
---Answer: The Elasticity of Demand is 1.

Why It Matters

Understanding elasticity helps businesses decide how to price their products, like how an EV company prices its new car. It's crucial for economists to predict market changes and for FinTech companies to analyze consumer spending. This skill is used by market researchers and business strategists to make smart decisions.

Common Mistakes

MISTAKE: Confusing Elasticity of Demand with just 'change in demand'. | CORRECTION: Elasticity is about the *percentage* change in demand relative to the *percentage* change in price, not just the absolute numbers.

MISTAKE: Forgetting to take the absolute value of the result. | CORRECTION: Elasticity of Demand is usually expressed as a positive number, even though the formula often gives a negative value (because price and demand move in opposite directions).

MISTAKE: Using the wrong initial values for percentage change calculation. | CORRECTION: Always use the *original* (initial) price and quantity in the denominator when calculating percentage changes.

Practice Questions

Try It Yourself

QUESTION: If the price of a chai increases from Rs 10 to Rs 11, and daily sales drop from 200 cups to 180 cups, what is the Elasticity of Demand? | ANSWER: -1 (or 1 in absolute terms)

QUESTION: A new smartphone costs Rs 20,000, and 5000 units are sold. When its price drops to Rs 18,000, sales jump to 6000 units. Calculate the Elasticity of Demand. | ANSWER: -2 (or 2 in absolute terms)

QUESTION: A local cinema sells 100 tickets at Rs 150 each. To increase revenue, they consider two options: Option A: Increase price to Rs 180, expecting sales to drop to 85 tickets. Option B: Decrease price to Rs 120, expecting sales to rise to 130 tickets. Which option results in a more elastic demand? Calculate elasticity for both. | ANSWER: Option A: -0.75 (inelastic). Option B: -1.5 (elastic). Option B results in more elastic demand.

MCQ

Quick Quiz

If the price of petrol increases by 10% and the quantity demanded decreases by 2%, what can we say about the demand for petrol?

It is elastic

It is inelastic

It has unit elasticity

It is perfectly elastic

The Correct Answer Is:

If the percentage change in quantity demanded (2%) is less than the percentage change in price (10%), the demand is inelastic. People still buy petrol even if the price goes up a lot.

Real World Connection

In the Real World

Online food delivery apps like Zomato or Swiggy use Elasticity of Demand to decide surge pricing during peak hours or discounts during off-peak times. They analyse how much people are willing to pay extra for quick delivery or if a discount will bring in many more orders. This helps them maximise profits and manage delivery rider availability.

Key Vocabulary

Key Terms

DEMAND: The quantity of a good or service that consumers are willing and able to purchase at various prices during a specific period. | PRICE: The amount of money that has to be paid to acquire a product or service. | ELASTIC: When a small change in price leads to a large change in quantity demanded. | INELASTIC: When a change in price leads to a relatively small change in quantity demanded. | PERCENTAGE CHANGE: The relative change between two numbers, expressed as a percentage.

What's Next

What to Learn Next

Great job understanding Elasticity of Demand! Next, explore 'Factors Affecting Elasticity of Demand'. This will help you understand *why* some products are elastic and others are inelastic, making you a super-smart economist!