Which market structure is defined by a small number of large firms with interdependent pricing?

• A. Perfect competition
• B. Monopoly
• C. Monopolistic competition
• D. Oligopoly

Answer: (D)

Pricing in a market with a small number of large firms happens in an oligopoly, where each company's profits depend on anticipating and reacting to the pricing moves of the other big players. Because there aren’t many competitors, a price change by one firm invites a response from the others, making pricing decisions highly strategic. This interdependence often leads to price stability, since a sudden move by one firm could trigger similar moves by others and erode profits for all. Firms in this structure may also rely on non-price competition, like branding, service differences, or product features, to protect market share without sparking a price war. For example, on key routes or in major tech markets, a few dominant firms monitor rivals closely and adjust not just on price but through strategic choices that influence demand. By contrast, perfect competition has many firms with no individual influence on price, a monopoly involves a single price-setting firm, and monopolistic competition features many firms with differentiated products and less direct interdependence among prices.