💸principles of economics review

Downward Sloping Demand

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Downward sloping demand refers to the inverse relationship between the price of a good or service and the quantity demanded of that item. As the price increases, the quantity demanded decreases, and vice versa. This fundamental economic principle is known as the law of demand.

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5 Must Know Facts For Your Next Test

  1. The downward sloping demand curve reflects the diminishing marginal utility consumers experience as they consume more of a good or service.
  2. A monopoly faces a downward sloping demand curve, unlike a perfectly competitive firm that faces a horizontal demand curve at the market price.
  3. The downward sloping demand curve for a monopoly limits the firm's ability to raise prices without experiencing a significant decrease in quantity demanded.
  4. The area under the downward sloping demand curve represents the total consumer surplus, which is maximized under perfect competition but reduced under monopoly.
  5. The downward sloping demand curve is a key factor in a monopoly's profit-maximizing decision, as it determines the relationship between price and quantity sold.

Review Questions

  • Explain how the downward sloping demand curve affects a monopoly's pricing and output decisions.
    • The downward sloping demand curve faced by a monopoly means that as the firm raises its price, the quantity demanded decreases. This inverse relationship between price and quantity limits the monopoly's ability to raise prices without experiencing a significant decline in sales. To maximize profits, the monopoly will produce the quantity where marginal revenue equals marginal cost, which is lower than the output level that would maximize social welfare under perfect competition.
  • Describe how the downward sloping demand curve influences the relationship between a monopoly's marginal revenue and market price.
    • For a monopoly, the downward sloping demand curve means that each additional unit sold commands a lower price. As a result, the marginal revenue earned from selling an additional unit is less than the market price. This is because the monopoly must lower the price on all units sold to sell an additional unit, reducing the firm's total revenue. The difference between the market price and marginal revenue is a key factor in the monopoly's profit-maximizing decision-making process.
  • Analyze how the downward sloping demand curve affects the distribution of consumer and producer surplus under monopoly compared to perfect competition.
    • Under perfect competition, the horizontal demand curve means that the market price equals the marginal revenue for each unit sold. This results in the maximum possible consumer surplus, as the market price is equal to the marginal willingness to pay for each unit. In contrast, the downward sloping demand curve faced by a monopoly means that the market price is higher, and the quantity produced is lower, than the socially optimal level. This results in a smaller total surplus, with a greater proportion of that surplus accruing to the monopoly as producer surplus, rather than to consumers as consumer surplus.