In-Depth Notes on Elasticity and Demand Curves

Demand Curves & Elasticity: Steep demand curves are relatively inelastic; flat curves are relatively elastic. Elasticity changes along a straight-line demand curve.
Understanding Points on the Demand Curve:
- At the top of the demand curve:
- High price, low quantity demanded.
- Small % change in price, large % change in quantity → results in high elasticity.
- At the bottom of the demand curve:
- Low price, high quantity demanded.
- Large % change in price, small % change in quantity → results in low elasticity.
Elastic vs. Inelastic Demand:
- Elastic Demand: Elasticity > -1 (in absolute terms > 1)
- Inelastic Demand: Elasticity < -1 (in absolute terms < 1)
- Unitary Elasticity: Elasticity = -1, occurs halfway along the demand curve.
Marginal Revenue Curve:
- Crosses quantity axis at point where elasticity is unitary (elasticity = -1).
- This point is also where marginal revenue = 0, defining where firms maximize their revenue.
Key Takeaways: Demand curves cannot be classified simply as elastic or inelastic because elasticity varies along the curve. Firms must recognize that consumers become more price-sensitive as prices rise.

Profit Maximizing Quantity: For firms maximizing profit, marginal cost must equal marginal revenue. Firms operate in the elastic region of the demand curve to ensure elasticity is always greater than 1.
Implication of Demand Elasticity in Profit Maximization:
- When profit-maximizing, if elasticity is less than one, this indicates the firm is not maximizing its potential profit and should consider raising prices.
- Firms with market power inherently have elastic demand.

Total Revenue & Elastic Demand:
- In the elastic portion of the demand curve (upper half), decreasing prices increases total revenue.
- Oppositely, inelastic demand (lower half), decreasing prices leads to decreased total revenue.
- The point where marginal revenue equals 0 (and thus total revenue is maximized) is at unit elasticity.

Understanding Pricing Decisions: The pricing this firm sets depends on where it operates along the demand curve, which influences how changes in costs affect pricing strategy.
If costs decrease, firms may typically maintain prices instead of reducing them, as lower prices can harm profits if it leads to competitors reducing their prices as well.

Price Discrimination Basics: Price discrimination is charging different prices to different consumers; it's crucial for firms to differentiate their consumers based on elasticity of demand.
Requirements for Price Discrimination:
1. Heterogeneous demand among consumers.
2. Ability to distinguish between consumer types.
3. Prevent transfer sales between consumer groups.

First Degree Price Discrimination: Personalized pricing where each consumer is charged based on their willingness to pay. Practically, this is difficult due to lack of information on consumer willingness.
Dynamic Pricing Example: Amazon offering different prices to consumers based on their behaviors follows this logic, customizing offers without perfect information.

Second Degree Price Discrimination: Offering decreasing prices for additional units purchased to capture the remaining consumer surplus when consumers buy in bulk.
Third Degree Price Discrimination: Includes methods like group pricing (charging different groups different prices) and menu pricing (offering options appealing to different demand elasticity levels).
Examples like movie theaters charging students and seniors less depict third-degree price discrimination.

Implications for Firms & Competition:
- Recognize consumer price sensitivity changes with pricing.
- Understand that profit-maximizing firms operate where demand is elastic, leading to different pricing strategies based on consumer characterization.
- Companies use market segmentation to assign prices based on willingness to pay, which can vary by demographic and economic status.