How much pricing power a firm has depends on its market structure, ordered by fading competition across four canonical cases.
In perfect competition, many sellers offer identical products with free entry. Each firm is a price taker: it can sell any amount at the market price but nothing above it.
In monopolistic competition, many sellers offer differentiated products. Each restaurant or brand is slightly unique, granting a little pricing power while free entry drives long-run profits to zero.
In an oligopoly, a few large sellers dominate. Pricing is strategic since each firm's best move depends on rivals' moves.
In a monopoly, one seller with no close substitutes faces blocked entry and acts as a price maker, choosing the profit-maximizing point on the demand curve.
Structure Diagnostic
| Structure | Sellers | Product | Entry | Pricing power |
|---|---|---|---|---|
| Perfect comp | Many | Identical | Free | None, price taker |
| Monop comp | Many | Differentiated | Free | A little |
| Oligopoly | Few | Similar/Diff | Hard | Strategic |
| Monopoly | One | Unique | Blocked | Full, price maker |
What decides the structure? Number of firms, product differentiation, and barriers to entry.
Strategic consequence: in perfect competition you win by cost; under differentiation you win by distinctiveness; in oligopoly you win by anticipating rivals; a monopoly wins by defending the barrier.
Pitfall: The real diagnostic is the entry barrier, not the current number of firms. A market with two firms and free entry behaves more competitively than one firm protected by a patent wall.