Econ Class 11

Elasticity of Demand

• Importance of Elasticity for Business Owners

  • Critical for developing pricing strategies.

  • Affects revenue and profit generation.

• Price Elasticity of Demand Calculation

  • Formula:
    $E_d = \frac{\text{Percentage Change in Quantity}}{\text{Percentage Change in Price}}$

  • Rearranging for predictions:

    • Allows forecasting quantity changes based on price changes.

    • Percentage change in quantity can be determined by multiplying elasticity by price change:
      $\text{Percentage Change in Quantity} = E_d \times \text{Percentage Change in Price}$

  • Example:

    • For strawberries, if price elasticity is -0.8 and price increases by 15%:

    • Calculation:
      $\text{Percentage Change in Quantity} = -0.8 \times 15\% = -12\%$

    • Interpretation: Quantity demanded decreases by 12%.

• Total Revenue Considerations

  • Total Revenue (TR):

    • Formula:
      $TR = \text{Price} \times \text{Quantity}$

  • Business focus on revenue generation, independent of cost factors.

  • Example:

    • Bakery sells 60 brownies at $2.25 each.

    • Total revenue:
      $TR = 2.25 \times 60 = 135\text{ dollars}$

    • Area under the demand curve illustrates total revenue graphically.

• Relationship Between Price Elasticity and Total Revenue

  • Demand curve: Downward sloping.

  • Impacts of changes in price and quantity on revenue.

  • Elastic Demand:

    • If elasticity > 1 (elastic):

    • Decreasing price leads to increased revenue (attracts more customers).

  • Inelastic Demand:

    • If elasticity < 1 (inelastic):

    • Increasing price leads to increased revenue (less sensitivity to price).

• Elastic vs Inelastic Demand

  • Elastic Demand:

    • Price and total revenue move in opposite directions.

    • E.g., Price decreases result in increased quantity demanded and hence higher total revenue.

  • Inelastic Demand:

    • Price and total revenue move in the same direction.

    • E.g., Price increases lead to increased revenue due to lesser change in quantity demanded.

• Examples of Revenue Changes with Price Changes

  • Elastic Demand:

    • Example graph shows that old revenue is larger, hence price increase leads to revenue loss.

  • Inelastic Demand:

    • Example graph shows new larger revenue area after price increase indicates revenue increase.

  • Summary:

    • Elastic products benefit from discounts; inelastic products benefit from price increases.

Understanding Elasticity through Examples and Exercises

• Elastic vs Inelastic Case Study

  • Concept Check:

    • Price raised by 15% and quantity demanded fell by 10%: Analyze elasticity.

    • Calculation:
      $E_d = \frac{-10\%}{15\%} = -\frac{2}{3}$

    • Interpretation: Inelastic because elasticity < 1.

• Demand Elasticities Beyond Price

  • Cross Price Elasticity of Demand

    • Formula:
      $E_{xy} = \frac{\text{Percentage Change in Quantity of X}}{\text{Percentage Change in Price of Y}}$

    • Significance of Relationships:

      • Substitutes yield positive values (increase in one’s price increases the demand of the other).

      • Complements yield negative values (increase in one’s price decreases the demand for the other).

      • Example:

        • Raspberries and blueberries:

        • Positive value of cross elasticity indicates they are substitutes:

        • E.g., Raspberry price up 8% increases blueberry demand by 12%.

        • $E_{xy} = \frac{12\%}{8\%}=1.5$

    • Scenarios:

    • Higher price of cereal = lower demand for milk (negative cross price elasticity indicates complement goods).

    • Higher price of cookies = higher demand for candy (positive cross price elasticity indicates substitute goods).

• Income Elasticity of Demand

  • Formula:
    $E_i = \frac{\text{Percentage Change in Quantity Demanded}}{\text{Percentage Change in Income}}$

  • Distinction Between Goods:

    • Normal goods: Income elasticity > 0 (demand increases as income increases).

    • Inferior goods: Income elasticity < 0 (demand decreases as income increases).

  • Examples:

    • Restaurant meals as normal goods.

    • Fast food as inferior goods as income rises.

    • Calculation of scenarios providing numerical examples for both normal and inferior goods.

    • Note: If demand increases with income (normal), if decreases (inferior).

    • Examples: Plane tickets (normal), fast food (inferior).

Final Notes

• Importance of Understanding Elasticity for Decision Making

  • Affects pricing strategies based on consumer sensitivity to price.

  • Helps to determine revenue maximizing strategies based on product demand elasticity.

  • Ability to forecast changes in revenue based on elasticity can guide business decisions effectively.

• Future Topics

  • Exploring advanced concepts within demand elasticity such as opportunity costs and market dynamics impacting demand changes.