Define monopoly. How are price and output determined under it? [3+7] GROUP: B Short answer questions 4 × 5 = 20

Definition of Monopoly

A monopoly is a market structure characterized by the presence of a single seller of a unique product (with no close substitutes) in the entire industry. This single firm enjoys absolute control over the market, acting as the sole supplier of the product. Key features of a monopoly include:

• Single Seller: Only one firm dominates the market.
• No Close Substitutes: The product has no close substitutes, making demand highly inelastic.
• Price Maker: The monopolist has the power to influence and set the price of the product.
• Barriers to Entry: High barriers (e.g., legal restrictions, high capital requirements, or economies of scale) prevent new firms from entering the market.
• Price Discrimination: The monopolist may charge different prices to different consumers based on their willingness to pay.

---

Determination of Price and Output in Monopoly

Unlike perfect competition, where price equals marginal cost (P = MC), a monopolist determines both price and output based on profit maximization. The monopolist maximizes profit where Marginal Revenue (MR) equals Marginal Cost (MC). However, the price charged is determined from the demand curve (AR), not the MR curve.

Steps to Determine Price and Output

1. Demand Curve (AR): The monopolist faces a downward-sloping demand curve because it is the sole seller. The Average Revenue (AR) curve is the same as the demand curve.
2. Marginal Revenue (MR) Curve: The MR curve lies below the demand curve and is steeper. It represents the additional revenue gained from selling one more unit.
3. Marginal Cost (MC) Curve: The MC curve shows the cost of producing an additional unit. It typically rises with output due to diminishing returns.
4. Profit Maximization Condition: The monopolist produces where MR = MC. This gives the profit-maximizing quantity (Q)*.
5. Price Determination: Once Q* is determined, the monopolist moves upward to the demand curve (AR) to find the price (P*) that consumers are willing to pay for that quantity.

Graphical Explanation

From the figure above:

• The MR curve intersects MC at Q = 3 units*.
• The corresponding price (P*) is found on the demand curve (AR) at P = 7*.
• The monopolist produces less output (Q = 3)* and charges a higher price (P = 7)* compared to a perfectly competitive firm (where P = MC).

Why Does a Monopolist Restrict Output?

• In perfect competition, P = MC, and firms produce where AR = MC.
• A monopolist, however, faces a downward-sloping demand curve, meaning that to sell more, it must reduce the price.
• Since MR < AR, the monopolist restricts output to maintain a higher price, thereby maximizing profit (represented by the shaded area in the figure).

Comparison with Perfect Competition

Mathematical Explanation (Optional for NEB)

Suppose a monopolist’s demand function is: $$P=10-Q$$ Total Revenue (TR) = $P\times Q=10Q-Q^2$ Marginal Revenue (MR) = $\frac{d(TR)}{dQ}=10-2Q$

Assume MC is constant at MC = 2.

Profit Maximization Condition (MR = MC): $$10-2Q=2$$ $$2Q=8$$ $$Q\ast =4$$

Price (P) from Demand Curve:* $$P=10-Q\ast =10-4=6$$

Thus, the monopolist produces 4 units at a price of 6, earning supernormal profit.

---

Conclusion

A monopoly is a market structure where a single firm dominates the industry, setting both price and output to maximize profit. Unlike perfect competition, the monopolist restricts output and charges a higher price, leading to market inefficiency (deadweight loss). The equilibrium is determined where MR = MC, and the price is read from the demand curve.