Study Notes on Demand Elasticity and Price Elasticity of Supply

Introduction to Demand Elasticity

  • Definition: Demand elasticity refers to how sensitive the quantity demanded of a good or service is to changes in its price.

  • Importance: Understanding demand elasticity helps businesses forecast revenues and shape their overall business strategy.

Different Aspects of Demand Elasticity

  • Price Elasticity of Demand (PED):

    • Formula:
      extPED=racextPercentageChangeinQuantityDemandedextPercentageChangeinPriceext{PED} = rac{ ext{Percentage Change in Quantity Demanded}}{ ext{Percentage Change in Price}}

    • Interpretation: The elasticity of demand can tell us how much the quantity demanded will change in response to a price change.

    • Analysis based on elasticity types:

    • Elastic Demand (elasticity > 1): Consumers are highly responsive to price changes.

    • Inelastic Demand (elasticity < 1): Quantity demanded changes less than the price change.

    • Unitary Elastic Demand (elasticity = 1): Changes in quantity demanded equal changes in price.

Total Revenue Calculation

  • Total Revenue (TR):

    • Definition: Total revenue is calculated as the product of the price per unit and the quantity sold.

    • Formula:
      extTotalRevenue=extPriceimesextQuantityext{Total Revenue} = ext{Price} imes ext{Quantity}

    • Importance in elasticity context: Depending on elasticity, changes in price can result in varying impacts on total revenue:

    • If demand is elastic, reducing the price can increase total revenue.

    • If demand is inelastic, reducing the price can decrease total revenue.

Examining Demand Curves

  • Elastic Demand Curve Example:

    • Starting Price: $1.50; Quantity Sold: 1,000 units; Total Revenue: $1,500.

    • After Price Decrease to $1.35: Quantity Sold: 1,200 units; New Total Revenue: $1,620.

    • Analysis: Revenue increased despite lowering price due to a significant increase in quantity sold.

  • Inelastic Demand Curve Example:

    • Starting Price: $1.50; Quantity Sold: 1,000 units; Total Revenue: $1,500.

    • After Price Decrease to $1.35: Quantity Sold: 1,050 units; New Total Revenue: $1,417.50.

    • Analysis: Revenue decreased due to insufficient increase in quantity sold to offset the price reduction.

Strategic Pricing Decisions

  • When demand is elastic: Reduce prices to increase total revenue.

  • When demand is inelastic: Increase prices to maximize total revenue.

Example Scenario of Elasticity

  • Substitution Effect: If every student in a class becomes a tutor, it implies many substitutes exist making demand for each tutor’s service elastic. To increase total revenue, they need to decrease session prices.

Graphical Interpretation of Demand Elasticity

  • Understanding directionality of changes:

    • Elastic Demand: Price increase → Total Revenue decrease.

    • Inelastic Demand: Price increase → Total Revenue increase.

    • Unitary Elasticity: No change in total revenue with price changes.

Market Structure's Impact on Pricing Strategy

  • In perfectly competitive markets: Sellers are price takers; cannot influence the price.

  • In other market structures: Understanding price elasticity of demand is essential for making strategic price changes.

Additional Demand Elasticities

  • Cross Price Elasticity of Demand: Measures responsiveness of quantity demanded of one good in response to price change of another.

    • Formula:
      extCrossPriceElasticity=racextPercentageChangeinQuantityDemandedofGoodXextPercentageChangeinPriceofGoodYext{Cross Price Elasticity} = rac{ ext{Percentage Change in Quantity Demanded of Good X}}{ ext{Percentage Change in Price of Good Y}}

    • Positive Sign: Goods are substitutes (e.g., Coke and Pepsi).

    • Negative Sign: Goods are complements (e.g., CD and CD player).

  • Income Elasticity of Demand: Measures responsiveness of demand to changes in income.

    • Formula:
      extIncomeElasticity=racextPercentageChangeinQuantityDemandedextPercentageChangeinIncomeext{Income Elasticity} = rac{ ext{Percentage Change in Quantity Demanded}}{ ext{Percentage Change in Income}}

    • Positive Value: Normal good (demand rises with income).

    • Negative Value: Inferior good (demand falls with income).

Price Elasticity of Supply

  • Definition: Measures how responsive quantity supplied is to price changes.

  • Formula:
    extPriceElasticityofSupply=racextPercentageChangeinQuantitySuppliedextPercentageChangeinPriceext{Price Elasticity of Supply} = rac{ ext{Percentage Change in Quantity Supplied}}{ ext{Percentage Change in Price}}

  • Typically a positive value as higher prices lead to higher quantities supplied.

Determinants of Price Elasticity of Supply

  • Flexibility of Production:

    • More flexible production leads to more elastic supply. Factors include:

    • Availability of inventory: Easier to adjust supplies.

    • Availability of inputs: Readily available materials increase elasticity.

    • Capacity utilization: Firms producing below capacity can easily adjust supply.

    • Entry and Exit barriers: Easy entry/exit raises elasticity.

    • Time: Supply becomes more elastic over a longer time horizon.

Examples of Price Elasticity of Supply

  • Calculation Example:

    • Quantity supplied increases from 2 million to 4 million with a price increase from $600 to $700.

    • Calculate changes and elasticity to determine responsiveness.

  • Another Scenario: Given PES = 1.2, to raise supply by 15%, calculate the percentage price increase required.

Conclusion of Chapter 5

  • Key Takeaways: Mastery of elasticity concepts is critical for success in economics. Understanding the dynamics of supply and demand helps in making informed pricing and production decisions.