Oligopoly

Topic: Market Structures, Market Failure and Competition · NCERT: Beyond NCERT

Meaning

Oligopoly is a market with a few large sellers, where each firm's best price or output depends on what its rivals do. This dependence is called mutual interdependence. Entry barriers keep the number of firms small.

It matters because a few firms can quietly act together. When that happens, prices stay high or stop moving even when costs change. This is why oligopoly sits at the centre of competition law and of India's debates on telecom and aviation.

Explanation

Key features

• A few large sellers. Each one is big enough that its actions affect the whole market.
• Mutual interdependence. This is the key feature of oligopoly.
• Before a firm changes its price, it must guess how its rivals will react.

• No firm can decide alone.

• Significant entry barriers keep the number of firms small. Examples are scale economies (costs per unit fall only at very large output), licences, spectrum and airport slots.

• The product can be of two kinds:
• Homogeneous (identical), such as cement or steel.

• Differentiated (slightly different), such as cars or airline services.

• Two results follow from having few firms that depend on each other:

• there is room for collusion, meaning rivals cooperate to limit competition;

• prices tend to be rigid, meaning they are sticky and rarely change.

• No single model. The outcome depends on what each firm assumes about its rivals. That is why there are many oligopoly models.

Models: quantity, price and sticky prices

• Duopoly is an oligopoly with only two sellers. It is a special case of oligopoly.
• Cournot model (1838): firms compete on quantity.
• Each firm chooses its output and treats its rival's output as fixed.

• The price ends up between the monopoly price and the competitive price.

• Bertrand model (1883): firms compete on price, and the products are identical.

• Each firm can win the whole market by charging slightly less than its rival.
• This undercutting continues until P = MC (price equals marginal cost, the cost of making one more unit).

• So the competitive price is reached with only two firms. This is the Bertrand paradox.

• Worked example. Market demand is P = 100 − Q. Each firm has MC = ₹10.

Structure	Total output (Q)	Price (P)
Monopoly (MR = MC: 100 − 2Q = 10)	45	₹55
Cournot duopoly (each firm makes (100 − 10)/3 = 30)	60	₹40
Bertrand duopoly	90	₹10 (= MC)
Perfect competition	90	₹10

• Kinked demand curve (Paul Sweezy, 1939): why prices stay sticky. Sweezy assumed that rivals match a price cut but ignore a price rise.
• If a firm raises its price, rivals do not follow, so it loses many buyers. Demand above the current price is elastic (buyers react strongly).
• If a firm cuts its price, rivals cut too, so it gains few buyers. Demand below the current price is inelastic (buyers react weakly).
• The result: the demand curve has a kink at the current price. The MR curve (marginal revenue, the extra money from selling one more unit) has a vertical gap below the kink.

• So cost changes do not move the price. MC can rise or fall inside this gap, and the firm keeps the same output and price.

• Worked example (kink).

• The price is ₹50. Just above the kink MR is ₹40, and just below it MR is ₹20.

• MC rises from ₹25 to ₹35. That is still inside the ₹20–₹40 gap, so the price stays at ₹50.

• Limits of the kinked model:

• It explains why a price stays where it is, but not how that price was reached.
• It does not fit periods of high inflation, when all firms raise prices together.

Coordination: price leadership, limit pricing and collusion

• Price leadership: one firm sets the price and the others follow, without any formal agreement. The leader can be:
• a dominant firm, the largest and often the lowest-cost firm; or

• a barometric firm, a firm that reads market conditions well even if it is not the largest.

• Limit pricing: the incumbent (the firm already in the market) keeps its price just low enough that entry does not pay.

• Example: the incumbent's AC (average cost, or cost per unit) is ₹60, and a new entrant's AC would be ₹70.

• The incumbent charges ₹68. It earns ₹8 per unit, but the entrant would lose ₹2 per unit, so it stays out.

• Collusion can be explicit or tacit:

• Explicit collusion is a written or spoken agreement. A cartel is the formal version: producers agree to fix prices, limit output or share markets, so that together they act like a monopoly. Cartels are illegal. OPEC/OPEC+ production quotas are the classic international example.

• Tacit collusion is parallel behaviour with no agreement, such as following a price leader. It is hard to prove, because similar prices can also come from similar costs.

• Why cartels break down: each member gains by cheating.

• Prisoner's dilemma example: if both firms keep to the quota, each earns ₹100 crore. If one cheats while the other keeps to it, the cheat earns ₹150 crore and the loyal firm earns ₹40 crore. If both cheat, each earns ₹60 crore.
• Cheating pays more whatever the rival does (₹150 > ₹100, and ₹60 > ₹40). So cheating is the dominant strategy (the best choice in every case).

• Both firms cheat, both end up with ₹60 crore, and the price falls back towards the competitive level.

• Contestability limits oligopoly power. In a contestable market (Baumol, Panzar and Willig, 1982), entry and exit are free and there are no sunk costs (costs that cannot be recovered when a firm leaves).

• The threat of hit-and-run entry forces even a few firms to charge competitive prices.
• Sunk costs such as airport slots, spectrum payments and tower networks weaken this threat.

In India

• The law. The Competition Act, 2002 is enforced by the Competition Commission of India (CCI).
• Cartel-type agreements that fix prices or limit production and supply breach Section 3(3)(a) and 3(3)(b) read with Section 3(1) [1].

• Bid rigging (competitors secretly agreeing who will win a tender) is also treated as cartel conduct. CCI has penalised it in tenders of Indian Railways [7] and the State Bank of India [8].

• Tyre cartel (CCI final order dated 31.08.2018):

• It covered Apollo, MRF, CEAT, JK Tyre and Birla Tyres, together with their association ATMA (Automotive Tyre Manufacturers Association) [1].
• They acted together to raise prices of cross-ply/bias tyres and to limit production and supply [1].
• How it worked: ATMA collected company-wise production, sales and export data in real time. Members used it to share price-sensitive information and take collective price decisions [1].

• The penalty was about ₹1,788 crore. Check the current appeal status.

• Cement: CCI penalised Shree Cement, UltraTech, Jaiprakash Associates, J.K. Cement, Ambuja, ACC and J.K. Lakshmi for bid rigging [2].

• Leniency: using the cheating incentive against cartels.
• Section 46 lets a cartel member apply for a lesser penalty if it gives full, true and vital disclosures about the cartel [1].
• The first CCI order under the lesser penalty provisions was about bid rigging in sports-broadcasting tenders [9].
• The Competition (Amendment) Act, 2023 (dated 11 April 2023) [5] added "lesser penalty plus" (LPP). An existing leniency applicant gets an extra reduction if it discloses another cartel that was not yet known [1][4].
• The CCI (Lesser Penalty) Regulations, 2024 were notified on 20.02.2024 [1].

• The same amendment added settlement and commitment for Section 3 and Section 4 cases, so markets can be corrected faster with less litigation [4].

• Scale of enforcement: CCI investigated 35 cartel cases in the last five years, according to a PIB release in 2025 [3]. In 2025 it registered 54 antitrust cases and received 149 merger (M&A) filings [6].

• Telecom: close to a duopoly.
• After the Supreme Court's AGR judgment (October 2019), the market moved close to a duopoly of Jio and Airtel, with a weakened Vodafone Idea and BSNL. AGR is adjusted gross revenue, the revenue on which licence fees are calculated.
• Tariff hikes came almost together in December 2019, November 2021 and July 2024. This is textbook price leadership or tacit coordination.
• India had 1,282.33 million wireless subscribers at the end of March 2026 [10].

• Even M2M (machine-to-machine) connections are concentrated. In March 2026 the shares were Airtel 62.15%, Jio 18.76%, Vodafone Idea 15.81% and BSNL 3.28% [10].

• Aviation: a tight duopoly.

• Jet Airways (2019) and Go First (2023) left the market.
• IndiGo holds about 64% of domestic traffic and the Air India group about 27% (2025; check the current figures).
• Airport slots act as a sunk-cost barrier that makes the market less contestable.

Don't confuse with

• Monopolistic competition: it has many small firms with free entry, so no firm needs to worry about its rivals' reactions. Oligopoly has few firms behind entry barriers, and every firm watches its rivals.
• Duopoly: it is not a separate market structure. It is a special case of oligopoly with exactly two sellers.
• Cartel vs tacit collusion: a cartel is a formal agreement and is illegal under Section 3. Tacit collusion is parallel behaviour with no agreement, such as following a price leader, and is hard to prove.
• Contestable market: a market with few firms can still behave competitively if there are no sunk costs. What matters is how easy it is to enter, not how many firms there are.

Prelims Hooks

• Mutual interdependence is the defining feature of oligopoly. Products can be homogeneous (cement, steel) or differentiated (cars, airlines).
• Cournot (1838) firms compete on quantity, and the price lies between monopoly and competition. Bertrand (1883) firms compete on price, and the price falls to MC even with two firms (the Bertrand paradox).
• Kinked demand curve (Sweezy, 1939): demand is elastic above the kink and inelastic below it. The gap in the MR curve explains price rigidity.
• Trap: tacit collusion has no agreement. A cartel is a formal agreement and is illegal under Section 3(3) of the Competition Act, 2002. The tyre cartel order is dated 31.08.2018 [1].
• Section 46 is the lesser penalty (leniency) provision. Lesser penalty plus came with the Competition (Amendment) Act, 2023, and the Lesser Penalty Regulations were notified on 20.02.2024 [1][5].
• Contestable markets (Baumol, Panzar and Willig, 1982): the key condition is zero sunk costs, not a large number of firms.

Mains Points

• Ease of entry matters more than the number of firms.
• Telecom (a near-duopoly with tariff hikes in 2019, 2021 and 2024) and aviation (IndiGo about 64%) are legally open to competition, but show little real rivalry.

• Policy should lower sunk-cost barriers, such as spectrum pricing and airport slots, so that these markets become contestable.

• Tacit collusion is hard to prove.

• Parallel prices can be innocent when firms have similar costs.
• So CCI looks for "plus factors", such as data exchange through a trade association (as ATMA did in the tyre case) [1].

• It also uses leniency and LPP, which turn the cartel's own cheating incentive into insider evidence [1][4].

• Enforcement is becoming faster, but deterrence is still needed.

• The 2023 settlement and commitment route [4][5] and CCI's 54 antitrust cases in 2025 [6] show a move from long court cases to quicker market correction.
• Firms will stop colluding only if penalties are large and appeals are settled on time.

Related concepts

• Monopolistic competition
• Duopoly
• Kinked demand curve
• Price leadership
• Limit pricing
• Contestable market
• Collusion
• Cartel

Read more

• Monopolistic competition, oligopoly and collusion