# Market Structures Business I · Economics of the Firm · https://tryals.app/learn/business-i/market-structures 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. ## Practice questions 7 of this lesson's 14 practice questions, with answers. The full set is in the app. ### 1. Match each structure to how a firm wins in it. **Answer:** - Perfect competition → Ruthless cost efficiency - Monopolistic competition → Distinctive product and brand - Oligopoly → Anticipating rivals’ moves - Monopoly → Defending the entry barrier **Why:** The structure dictates the strategy: cost, distinctiveness, game-playing, or moat-keeping. Page: https://tryals.app/practice/business-i/market-structures/match-each-structure-to-how-a-firm-wins-in-it ### 2. A farmer selling wheat and a pharmaceutical firm holding a patent face the same demand curve for their own product in name only. What is the actual difference? A. The pharmaceutical firm faces higher demand because its product is essential B. Both face the same curve; the difference is in their cost structures C. The farmer can raise prices only by increasing quality, which the patent holder need not do D. The farmer is a price taker; the patent holder chooses a point **Answer:** D. The farmer is a price taker; the patent holder chooses a point **Why:** Raise the wheat price by a cent and sales go to zero, that flat line is what 'price taker' means geometrically. The patent holder owns the market curve and picks a quantity on it, so market power is nothing more mysterious than the slope of the line you face. Page: https://tryals.app/practice/business-i/market-structures/a-farmer-selling-wheat-and-a-pharmaceutical-firm-holding-a-patent ### 3. A price taker in perfect competition faces a horizontal demand curve; a monopolist faces the market’s downward-sloping one. What does that difference imply about the cost of selling one more unit? A. That the price taker cannot sell more than a fixed quantity B. That the monopolist must cut the price on every unit to sell more C. That marginal revenue equals price for both, since both face the same market D. That the monopolist has higher production costs per unit **Answer:** B. That the monopolist must cut the price on every unit to sell more **Why:** The gap between price and marginal revenue is the whole of monopoly theory. Because MR < P, the monopolist stops short of the competitive quantity, and the deadweight loss is what sits in that gap. Page: https://tryals.app/practice/business-i/market-structures/a-price-taker-in-perfect-competition-faces-a-horizontal-demand-curve ### 4. Which features define perfect competition? A. Significant barriers to entry B. Identical (homogeneous) products C. Firms take the market price as given D. Many small sellers **Answer:** B. Identical (homogeneous) products; C. Firms take the market price as given; D. Many small sellers **Why:** Free entry, the *absence* of barriers, is the fourth pillar; barriers are what create the other structures. Page: https://tryals.app/practice/business-i/market-structures/which-features-define-perfect-competition ### 5. In monopolistic competition, firms earn large economic profits in the long run. **Answer:** False **Why:** Free entry does its work: profitable niches attract imitators until economic profit is competed toward zero. Differentiation buys short-run pricing power, not a permanent moat. Page: https://tryals.app/practice/business-i/market-structures/in-monopolistic-competition-firms-earn-large-economic-profits-in-the ### 6. Monopolistic competition has many firms like perfect competition, yet each sets its own price. What makes the difference? A. Barriers to entry, which exist in monopolistic competition but not perfect competition B. Product differentiation, giving each a downward-sloping curve C. The smaller number of firms in monopolistic competition D. Government regulation of prices in one case but not the other **Answer:** B. Product differentiation, giving each a downward-sloping curve **Why:** Differentiation buys a sliver of pricing power. The pizzeria loses some customers but not all; the commodity seller loses all of them, which is what "price taker" means. Page: https://tryals.app/practice/business-i/market-structures/monopolistic-competition-has-many-firms-like-perfect-competition-yet ### 7. Sort each barrier to entry by its source. **Answer:** - Legal barrier: A 20-year pharmaceutical patent, A taxi license quota set by the city - Economic barrier: A rail network too costly to duplicate - Strategic barrier: Incumbent slashes prices whenever an entrant appears **Why:** Law grants some walls, cost structure builds others, and incumbents actively dig the rest. Page: https://tryals.app/practice/business-i/market-structures/sort-each-barrier-to-entry-by-its-source