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Market Structure: Monopoly

Microeconomics for Business · BBS · Updated Apr 23, 2026

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Market Structure: Monopoly

A monopoly exists when a single seller dominates the entire market with no close substitutes. The monopolist is a price maker.

Sources of Monopoly Power

Legal barriers: patents, copyrights, government licenses (Nepal Electricity Authority historically). Natural monopoly: single firm serves entire market at lower cost due to enormous economies of scale (electricity distribution, water supply). Control of essential resources: owning the only source of a key input. Brand loyalty and network effects: strong brands or platform effects (Google search, Facebook).

Revenue in Monopoly

Monopolist faces entire market demand curve — downward-sloping. To sell more, must lower price on ALL units. Therefore MR < P. MR curve lies below demand curve with twice the slope. TR maximised where MR = 0. Monopolist operates in elastic portion of demand curve.

Profit Maximisation

Maximise profit where MR = MC. Then charge price from demand curve: P > MR = MC. The difference P − MC = markup (monopolist’s pricing power). Monopoly profit = (P − ATC) × Q. Unlike perfect competition, profits persist in long run because barriers prevent entry.

Inefficiency

Compared to perfect competition: less output (Qm < Qc) and higher price (Pm > Pc). Creates deadweight loss — reduction in total surplus. Allocative inefficiency (P > MC). Productive inefficiency (may not produce at minimum ATC — X-inefficiency).

Price Discrimination

First-degree: charge each consumer maximum willingness to pay. Second-degree: different prices for different quantities (bulk discounts). Third-degree: different prices to different segments (student discounts, peak pricing). Conditions: market power, identifiable groups with different elasticities, prevention of resale.

Government Regulation

Price controls (P = MC for allocative efficiency, or P = ATC for normal profit). Antitrust laws. Nationalisation (Nepal Telecom historically). Encouraging competition (Nepal’s telecom became competitive after licensing Ncell). Regulation of natural monopolies.

Summary

Monopoly results in higher prices, lower output, and deadweight loss versus perfect competition. Price discrimination, government regulation, and the trade-off between efficiency and innovation are key themes.

Perfect Competition vs Monopoly Comparison

FeaturePerfect CompetitionMonopoly
Number of firmsVery manyOne
ProductHomogeneous (identical)Unique (no close substitutes)
Entry barriersNone (free entry/exit)High (legal, natural, technological)
Price settingPrice taker (accepts market price)Price maker (sets own price)
Demand curvePerfectly elastic (horizontal)Downward sloping (market demand)
MR vs PriceMR = P = ARMR < P (MR below demand curve)
Profit maximisationP = MCMR = MC, then price from demand curve
Long-run profitNormal profit only (zero economic)Supernormal profit can persist
EfficiencyAllocative (P=MC) + Productive (min ATC)Neither — deadweight loss exists
Consumer surplusMaximumReduced (transferred to producer)
Nepal exampleRice farmers in Terai (approximately)Nepal Electricity Authority (historically)

Worked Example: Monopoly Profit

A monopolist faces demand: P = 100 − 2Q, and has TC = 20 + 10Q + Q².

Step 1: Find TR = P × Q = (100−2Q)Q = 100Q − 2Q²

Step 2: Find MR = dTR/dQ = 100 − 4Q

Step 3: Find MC = dTC/dQ = 10 + 2Q

Step 4: Set MR = MC: 100 − 4Q = 10 + 2Q → 90 = 6Q → Q = 15 units

Step 5: Price from demand: P = 100 − 2(15) = Rs 70

Step 6: Profit = TR − TC = (70×15) − (20+10×15+15²) = 1050 − (20+150+225) = 1050 − 395 = Rs 655 supernormal profit

Note: Under perfect competition, P = MC: P = 10 + 2Q, and from demand 100−2Q = 10+2Q → Q = 22.5, P = Rs 55. So monopoly produces LESS (15 < 22.5) and charges MORE (70 > 55), creating deadweight loss.

Price Discrimination Types

DegreeMethodNepal Example
First (Perfect)Each consumer pays maximum willingness to payAuto-rickshaw bargaining in Kathmandu (different tourists pay different prices)
SecondDifferent prices for different quantitiesNEA electricity tariff — lower rate for first 20 units, higher for above
ThirdDifferent prices to different groupsMovie tickets: Rs 150 for students, Rs 300 for adults at QFX Cinemas

Exam Tips

Tip 1: Perfect competition vs monopoly comparison table is the MOST commonly asked market structure question. Tip 2: Monopoly profit calculation (MR=MC, find Q, find P from demand, calculate profit) is frequently tested numerically. Tip 3: Price discrimination types with Nepal examples shows practical understanding. Tip 4: Always mention deadweight loss and explain why monopoly is allocatively inefficient (P > MC).

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