What is the difference in price-setting between perfect competition and a monopoly?

• A. In perfect competition, many firms; price determined by market; firms are price takers. In a monopoly, a single firm sets the price (subject to demand).
• B. In perfect competition, firms collude to set prices; monopoly prices set by government.
• C. In perfect competition, government sets prices; monopoly prices determined by supply.
• D. In perfect competition, prices randomly set; monopoly has fixed price equal to marginal cost.

Answer: (A)

The key idea is who has control over the price. In a perfectly competitive market, many firms produce identical goods, so no single firm can influence the going price. The market price is determined by overall supply and demand, and each firm takes that price as given while deciding how much to produce. If a firm tried to raise its price above the market level, buyers would switch to other sellers, and the firm would lose sales. So firms are price takers and the price is set by the market.

In a monopoly, there is only one seller, so that firm has real market power to set the price. It faces the downward-sloping demand for its product, meaning it can influence price by adjusting output. The monopolist chooses the quantity where marginal revenue equals marginal cost to maximize profit, typically charging a price above marginal cost and producing less than the competitive quantity. Because it’s the sole supplier, it effectively sets the price rather than taking it from the market.

So the difference in price-setting is that competition-based markets relay price determination to the market, while a monopoly assigns price itself based on demand and its own output choice.