Monopolistic competition, oligopoly and collusion

Detail

1. Monopolistic competition — the basic idea

• Monopolistic competition was explained by Edward Chamberlin and Joan Robinson (1933). It is a market with:
• many firms, each small compared with the whole market;
• differentiated products (similar goods that buyers see as a little different because of brand, taste, design or location);
• free entry and exit, so new firms can join and loss-making firms can leave;

• some price-setting power, because each brand has loyal buyers.

• Examples: restaurants, branded clothing, soaps.

• Where it sits: it has the "many firms, free entry" of perfect competition and the "own product, some price power" of monopoly.
• Demand curve: it slopes downward because of differentiation. It is flatter (more elastic) than a monopolist's curve because many close substitutes exist.
• Profit rule: like any firm, it produces where MR = MC (marginal revenue, the extra money from selling one more unit, equals marginal cost, the extra cost of making one more unit). It then charges the price that its demand curve (AR) allows at that output.

2. Short run and long run under monopolistic competition

• Short run: a firm can earn supernormal profit, meaning profit above the minimum needed to keep it in business. This happens when P > AC, where AC is average cost (cost per unit).
• Long run: how entry removes the profit
• Supernormal profit attracts new entrants.
• Buyers spread across more brands, so each firm's demand curve (AR) shifts left.
• This continues until AR just touches (is tangent to) the AC curve.

• At that tangency, P = AC, so the firm earns only normal profit (just enough to stay in business). This is the Chamberlin tangency solution.

• Losses work in reverse: some firms exit, demand for the firms that remain moves right, and the market settles again at P = AC.

• Worked example:
• Short run: a restaurant sells 100 meals at ₹200. AC = ₹150, so profit = (200 − 150) × 100 = ₹5,000 of supernormal profit.
• New cafés open nearby. Its demand falls, and it ends up selling 80 meals at ₹170 with AC = ₹170.
• Profit is now (170 − 170) × 80 = 0 supernormal profit. Only normal profit is left.

3. Excess capacity and efficiency

• Excess capacity:
• AR slopes downward, so it can touch the U-shaped AC curve only on AC's falling part.
• That point lies to the left of minimum AC.

• So the firm produces less than the lowest-cost output. The unused capacity is called excess capacity.

• Not productively efficient: productive efficiency means producing at the lowest possible cost, which is minimum AC. This firm is not at minimum AC.

• Not allocatively efficient: allocative efficiency means P = MC, so the price buyers pay equals the cost to society of the last unit. Here P > MC.
• Contrast with perfect competition (NCERT Class 12): a perfectly competitive firm in the long run produces at P = MR = MC = minimum AC. It has no excess capacity.
• The payoff is variety. Society accepts somewhat higher cost in return for choice, such as many soaps or many cuisines.
• Non-price competition: advertising and branding build buyer loyalty, which makes demand less elastic (buyers react less to price changes). This gives the firm more room to set prices. The cost is that advertising adds to AC.

4. Oligopoly — few sellers who depend on each other

• Oligopoly is a market with a few large sellers. Each firm's best price or output depends on what its rivals do. This is called mutual interdependence, and it is the key feature of oligopoly.
• Significant entry barriers, such as scale economies, licences, spectrum or airport slots, keep the number of firms small.
• The products may be homogeneous (identical, such as cement or steel) or differentiated (such as cars or airlines).
• Two results follow from having few, interdependent firms:
• there is room for collusion;

• prices tend to be rigid.

• No single oligopoly model exists. The outcome depends on what each firm assumes about its rivals, which is why there are many models (below).

5. Duopoly models — Cournot and Bertrand

• A duopoly is an oligopoly with only two sellers, whose pricing and output decisions depend on each other. It is a special case of oligopoly.
• Cournot model (1838): the firms compete on quantity
• Each firm chooses how much to produce and treats its rival's output as fixed.

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

• Bertrand model (1883): the firms compete on price, with identical products

• Each firm can take the whole market by charging slightly less than its rival.
• Undercutting continues until P = MC.

• 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 (P = MC)	90	₹10

• The Cournot price (₹40) lies between the monopoly price (₹55) and the competitive price (₹10).
• The Bertrand price is the same as the competitive price.

6. Kinked demand curve — why oligopoly prices are sticky

• Paul Sweezy (1939) assumed that rivals match a price cut but ignore a price rise.
• Above the current price, demand is elastic. If one firm raises its price, its rivals do not follow, so it loses many buyers.
• Below the current price, demand is inelastic. If one firm cuts its price, its rivals cut too, so it gains few buyers.
• The result is a kink at the current price, which creates a vertical gap (discontinuity) in the MR curve.
• MC can move up or down inside this gap and MR = MC still holds at the same output, so the price does not change.
• This explains price rigidity (sticky prices) in oligopoly.
• Worked example:
• The current price is ₹50. Just above the kink MR is ₹40, and just below it MR is ₹20.

• Suppose MC rises from ₹25 to ₹35. It stays within the ₹20–₹40 gap, so the price stays at ₹50.

• Limits of the model: it explains why a price stays where it is. It does not explain how that price was reached in the first place. It also does not fit periods of high inflation, when all firms raise prices together.

7. Price leadership, limit pricing and contestable markets

• Price leadership means one firm sets the price and the others follow. 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 though it may not be the largest.

• Price leadership coordinates prices without any formal agreement. It is a common form of tacit coordination.

• Limit pricing means the incumbent sets a price low enough that entry becomes unprofitable, while still earning some profit.

• Example: the incumbent's AC is ₹60 and a new entrant's AC would be ₹70. The incumbent charges ₹68.

• It still earns ₹8 per unit, but the entrant would lose ₹2 per unit, so it stays out.

• Contestable market (Baumol, Panzar and Willig, 1982) is a market with free and costless entry and exit, meaning there are no sunk costs (costs that cannot be recovered on exit).

• The threat of hit-and-run entry forces incumbents to price competitively, even if there are only a few firms.
• Lesson for policy: the number of firms matters less than how easy it is to enter.
• Examples: route entry in aviation (an airline can move aircraft to a profitable route) and open access in telecom.
• Sunk costs weaken contestability. Examples are airport slots, spectrum payments and tower networks.

8. Collusion and cartels

• Collusion is explicit or tacit cooperation among rivals to limit competition on price, output or markets.
• Explicit collusion is a written or spoken agreement.

• 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.

• A cartel is a formal agreement among independent producers to fix prices, limit output or share markets, so that together they act like a monopoly. It is illegal under competition law.

• International example: OPEC/OPEC+ production quotas.

• Indian law:

• Under the Competition Act, 2002, 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) [2].

• 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 [9] and the State Bank of India [10].

• Indian cartel cases:

• Tyre cartel:
  • The CCI final order was dated 31.08.2018. It covered Apollo, MRF, CEAT, JK Tyre and Birla Tyres and their association ATMA (Automotive Tyre Manufacturers Association) [2].
  • The firms acted together to raise prices of cross-ply/bias tyres and to limit production and supply [2].
  • How it worked: ATMA collected company-wise production, sales and export data in real time. Members shared price-sensitive data through it and took collective price decisions [2].
  • The penalty was about ₹1,788 crore (NCERT scaffold; verify the current appeal status).
• Cement cartel: CCI penalised Shree Cement, UltraTech, Jaiprakash Associates, J.K. Cement, Ambuja, ACC and J.K. Lakshmi for bid rigging [3]. This was separate from the larger cement price cartel case in the scaffold.

• Beer cartel (2021): from the scaffold.

• Scale of enforcement:

• CCI investigated 35 cartel cases in the last five years, according to a PIB release in 2025 [4].
• In 2025 it registered 54 antitrust cases and received 149 merger (M&A) filings [7].

9. Why cartels break down — and how leniency uses this

• Cheating incentive:
• When the others keep to the quota, the cartel price stays high.
• So each member gains by secretly producing more or quietly offering discounts.

• If every member cheats, output rises and the price falls back towards the competitive level.

• Prisoner's dilemma (developed in Section 5 of this topic):

• Payoff example: two firms each earn ₹100 crore if both keep to the quota. A firm that cheats while the other keeps to it earns ₹150 crore, and the loyal firm earns ₹40 crore. If both cheat, each earns ₹60 crore.

• Whatever the rival does, cheating pays more (₹150 > ₹100, and ₹60 > ₹40). So cheating is the dominant strategy, and both end up with ₹60 crore.

• Leniency programmes use this weakness:

• Under Section 46 of the Competition Act, a cartel member can apply for a lesser penalty if it gives full, true and vital disclosures about the cartel [2].
• This turns cartel members into informants, because each fears the other will report first.

• The first CCI order under the lesser penalty provisions involved bid rigging in sports-broadcasting tenders [11].

• Competition (Amendment) Act, 2023 (Act No. 9 of 2023, dated 11 April 2023) [6]:

• It added "lesser penalty plus" (LPP). An existing leniency applicant for one cartel gets an extra reduction if it discloses another, undisclosed cartel [2][5].
• The CCI (Lesser Penalty) Regulations, 2024 were notified on 20.02.2024 [2].
• Settlement and commitment:
  • A firm under inquiry for anti-competitive agreements (Section 3) or abuse of dominant position (Section 4) can now offer a settlement or commitment, meaning it promises changes in behaviour [5].
  • The aim is to reduce litigation and correct markets faster [5].
• The amendment also changed Sections 27, 48 and 64. CCI then issued regulations on how turnover is determined for penalties [5][8].

10. Market concentration in India

• Telecom:
• The AGR judgment (Supreme Court, October 2019) worsened the telecom dues crisis. AGR is adjusted gross revenue, the revenue on which licence fees are calculated.
• Private telecom is now close to a duopoly (Jio, Airtel), with a weakened Vodafone Idea and BSNL.
• Tariff hikes came almost together in December 2019, November 2021 and July 2024. This is textbook price leadership or tacit coordination in an oligopoly.
• Scale: India had 1,282.33 million wireless (mobile + fixed wireless access) subscribers at the end of March 2026 [12].

• M2M (machine-to-machine) cellular connections, March 2026: Airtel 62.15%, Jio 18.76%, Vodafone Idea 15.81% and BSNL 3.28% [12]. Even this niche segment is highly concentrated.

• Aviation:

• Jet Airways (2019) and Go First (2023) exited the market.
• IndiGo holds about 64% of domestic traffic and the Air India group about 27% (2025; verify the current figures). This is a tight duopoly.

• Airport slots are a sunk-cost barrier that weakens contestability.

• Why concentration matters:

• Few firms make tacit collusion easier and parallel price hikes more likely.
• Consumers have less choice.
• When one firm fails, the market becomes more fragile.

Prelims Hooks

• Monopolistic competition was developed by Chamberlin and Joan Robinson (1933). In long-run equilibrium, P = AC (normal profit) but P > MC, and output is left of minimum AC (excess capacity).
• 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.
• Kinked demand curve (Sweezy, 1939): a gap in MR explains price rigidity. It is elastic above the kink and inelastic below it.
• Contestable markets (Baumol, Panzar and Willig, 1982): the key condition is zero sunk costs (costless entry and exit), not the number of firms.
• Trap: tacit collusion has no agreement and is hard to prove. A cartel is a formal agreement and is illegal.
• Section 3(3) of the Competition Act, 2002 covers horizontal agreements that fix prices or limit output. The tyre cartel breached Sections 3(3)(a) and 3(3)(b) read with 3(1) (CCI order of 31.08.2018) [2].
• Section 46 is the lesser penalty (leniency) provision. "Lesser penalty plus" was added by the Competition (Amendment) Act, 2023, and the Lesser Penalty Regulations were notified on 20.02.2024 [2][6].
• Settlement and commitment under the 2023 amendment applies to Section 3 (agreements) and Section 4 (abuse of dominance) cases [5].
• OPEC/OPEC+ is the classic example of an international cartel that uses production quotas.

Mains Points

• Few firms or easy entry?
• Telecom (near-duopoly, synchronised tariff hikes in 2019, 2021 and 2024) and aviation (IndiGo about 64%) show that a sector can stay "competitive" in law while having little real rivalry.

• Policy should lower sunk-cost barriers, such as spectrum pricing and airport slots, so that markets become contestable. The number of firms matters less.

• Proving tacit collusion is the hard part of enforcement:

• Parallel pricing can be innocent, for example when costs are similar.

• So CCI relies on "plus factors", such as data exchange through trade associations (as ATMA did in the tyre case) [2], and on leniency and LPP to get insider evidence [2][5].

• Efficiency vs. variety:

• Monopolistic competition wastes some capacity (P > MC, not at minimum AC).
• In return, it gives variety and innovation, especially among MSME brands.

• The right response is consumer information and anti-deceptive-advertising rules, not price control.

• Faster, less adversarial enforcement:

• The 2023 amendment added settlement and commitment [5][6], and CCI handled 54 antitrust cases in 2025 [7].
• This moves enforcement from long litigation towards quicker market correction.
• Deterrence still depends on large penalties and on how appeals are resolved.