Market power (HL only)

Market Power

The ability of a firm to influence the market price of a good or service. A firm with market power is a price maker — it faces a downward-sloping demand curve and can set price above marginal cost. The degree of market power depends on the number of competitors, product differentiation, and barriers to entry. Perfectly competitive firms have zero market power; monopolies have maximum market power.

Market Structure

The characteristics of a market that determine the behaviour and performance of firms within it. Key characteristics: (1) Number of firms. (2) Nature of the product (homogeneous vs differentiated). (3) Barriers to entry and exit. (4) Degree of information available to buyers and sellers. (5) Degree of market power held by individual firms. Four main market structures: perfect competition, monopolistic competition, oligopoly, monopoly.

Industry

A group of firms producing the same or closely related products. EXAMPLE: The automobile industry, the pharmaceutical industry, the airline industry. Different from a market — an industry refers to the supply side; a market includes both supply and demand.

Firm

An economic unit that organises factors of production to produce goods or services for sale. Firms are assumed (in standard theory) to be profit maximisers — they aim to maximise the difference between total revenue and total cost.

Profit

The surplus of total revenue over total cost. Economic profit = Total Revenue (TR) − Total Cost (TC), where TC includes both explicit costs (actual payments) and implicit costs (opportunity costs of owner's resources). Normal profit = zero economic profit — the firm covers all costs including opportunity costs. Supernormal profit (abnormal profit) = economic profit > 0 — TR > TC including opportunity costs. Loss = economic profit < 0.

Normal Profit

The minimum level of profit necessary to keep a firm in its current line of production in the long run — it is the opportunity cost of the entrepreneur's resources. Normal profit is included in the firm's total costs (implicit cost). When a firm earns exactly normal profit: TR = TC (including opportunity costs) → economic profit = 0. Normal profit is the long-run equilibrium condition for perfectly competitive markets.

Supernormal Profit (Abnormal Profit)

Profit earned above normal profit — TR > TC (including opportunity costs) → economic profit > 0. Also called economic profit or excess profit. In perfectly competitive markets: supernormal profits attract new entrants → supply increases → price falls → supernormal profits are competed away in the long run. In monopoly and oligopoly: barriers to entry prevent this → firms can sustain supernormal profits in the long run.

Revenue Concepts

TOTAL REVENUE (TR) = Price × Quantity = P × Q. AVERAGE REVENUE (AR) = TR ÷ Q = P (for all market structures — AR always equals price). MARGINAL REVENUE (MR) = the additional revenue from selling one more unit = ΔTR ÷ ΔQ. For a price taker (perfect competition): MR = P = AR (horizontal demand curve). For a price maker (monopoly, oligopoly): MR < P = AR because to sell one more unit the firm must lower price on ALL units → MR < AR → MR curve lies below AR (demand) curve.

Average Revenue (AR)

Total Revenue divided by quantity: AR = TR/Q = (P×Q)/Q = P. Therefore the AR curve is the same as the demand curve faced by the firm. This is true for ALL market structures. For a price taker: AR = constant = market price (horizontal). For a price maker: AR = downward-sloping demand curve.

Marginal Revenue (MR)

The additional revenue gained from selling one more unit of output. MR = ΔTR/ΔQ. For a price maker facing a downward-sloping demand curve: to sell one more unit, the firm must lower its price on ALL units sold → the gain from selling one more unit is less than the price → MR < P = AR. The MR curve lies below and is steeper than the AR (demand) curve. For a linear demand curve: MR has the same Y-intercept and twice the slope of the demand curve (MR bisects the horizontal distance between the Y-axis and the demand curve).

DIAGRAM — AR and MR for a Price Maker

Draw axes: Y = Price/Revenue, X = Quantity. Draw a downward-sloping demand curve from upper-left — label "D = AR." Draw a second downward-sloping line steeper than D, starting from the same Y-intercept — label "MR." MR lies below AR at every quantity except zero. For a linear demand: if AR hits X-axis at quantity Q_max, MR hits X-axis at Q_max/2 (exactly halfway). Label Y-intercept (same for both), and the point where MR = 0 (at Q_max/2).

Profit Maximisation Rule

All profit-maximising firms — regardless of market structure — produce at the output level where Marginal Revenue = Marginal Cost (MR = MC). At this output: if MR > MC, producing one more unit adds more to revenue than to cost → profit increases → produce more. If MR < MC, producing one more unit adds more to cost than to revenue → profit falls → produce less. Profit is maximised where MR = MC. This is the universal profit-maximising condition.

Cost Concepts — Reminder

TOTAL COST (TC) = Total Fixed Cost (TFC) + Total Variable Cost (TVC). AVERAGE TOTAL COST (ATC) = TC/Q. AVERAGE FIXED COST (AFC) = TFC/Q (falls continuously as Q rises). AVERAGE VARIABLE COST (AVC) = TVC/Q. MARGINAL COST (MC) = ΔTC/ΔQ = additional cost of producing one more unit. MC curve is U-shaped (falls then rises due to law of diminishing returns). MC intersects ATC and AVC at their minimum points.

Profit on a Diagram

Profit per unit = AR − ATC = P − ATC. Total profit = (P − ATC) × Q. SUPERNORMAL PROFIT: shown as a rectangle above ATC, below price P, stretching to output Q. If P > ATC: supernormal profit. If P = ATC: normal profit (no economic profit). If P < ATC: loss (shown as rectangle below price, above ATC — shaded as a loss). Always identify whether the firm is making supernormal profit, normal profit, or a loss from the diagram.

Barriers to Entry

Factors that prevent or discourage new firms from entering a market and competing with existing firms. Types: (1) ECONOMIES OF SCALE — large incumbents have lower ATC; new entrants start small and cannot compete on cost. (2) LEGAL BARRIERS — patents, copyrights, government licences, franchises. (3) BRAND LOYALTY AND ADVERTISING — strong brand recognition (Coca-Cola, Apple) deters entry. (4) CONTROL OF ESSENTIAL RESOURCES — ownership of key inputs (De Beers and diamonds). (5) HIGH STARTUP COSTS — large capital requirements deter entry (aerospace, pharmaceuticals). (6) NETWORK EFFECTS — value of product increases with number of users → incumbent advantage (social media, operating systems). (7) PREDATORY PRICING — incumbent temporarily prices below cost to drive out entrants.

Perfect Competition

A theoretical market structure with: (1) Many buyers and many sellers — each too small to affect price. (2) Homogeneous (identical) product — no differentiation. (3) Perfect information — all buyers and sellers know all prices and product characteristics. (4) No barriers to entry or exit — firms can freely enter and leave. (5) No externalities. Result: each firm is a price taker — faces a perfectly elastic (horizontal) demand curve at the market price. P = MR = AR.

Perfect Competition — Short Run Equilibrium

In the short run, a perfectly competitive firm can earn supernormal profit, normal profit, or make a loss — depending on whether the market price is above, equal to, or below ATC. DIAGRAM: Draw horizontal demand curve (= MR = AR = P) at market price. Draw U-shaped MC and ATC curves. Profit-maximising output: where MC = MR (= P). If P > ATC at that output: supernormal profit rectangle above ATC. If P = ATC: normal profit. If AVC < P < ATC: loss but firm continues (covers variable costs). If P < AVC: firm shuts down in short run.

Shut-Down Condition (Short Run)

A firm shuts down in the SHORT RUN if price falls below Average Variable Cost (P < AVC) — it cannot cover its variable costs and is better off producing nothing (losses = fixed costs only). If AVC ≤ P < ATC: firm continues producing (covers variable costs and contributes to fixed costs). The AVC minimum point is the shut-down point. DIAGRAM: On the cost curves diagram, mark the minimum of AVC — if market price falls below this point, the firm shuts down.

Perfect Competition — Long Run Equilibrium

In the long run, supernormal profits attract new entrants (no barriers to entry) → market supply increases → price falls → supernormal profits are eliminated. Losses cause firms to exit → supply falls → price rises → losses eliminated. Long run equilibrium: P = MR = MC = ATC (minimum). Each firm earns exactly normal profit. Industry produces at the minimum point of ATC → PRODUCTIVE EFFICIENCY. P = MC → ALLOCATIVE EFFICIENCY. Perfect competition is the benchmark of economic efficiency.

DIAGRAM — Perfect Competition Long Run

LEFT diagram (market): supply and demand determining market price P. RIGHT diagram (firm): horizontal demand curve at P (= MR = AR). U-shaped MC and ATC curves. Profit-maximising output Q* where MC = MR. At Q: P = minimum ATC (demand curve is tangent to ATC at its minimum). No supernormal profit — firm earns exactly normal profit. Label: P = MC (allocative efficiency), P = min ATC (productive efficiency).

Perfect Competition — Efficiency

PRODUCTIVE EFFICIENCY: P = minimum ATC in long run → goods produced at lowest possible cost. ALLOCATIVE EFFICIENCY: P = MC → price consumers pay = marginal cost of production → resources allocated to highest-valued uses → total surplus maximised. DYNAMIC EFFICIENCY: limited — firms have less incentive to innovate (no supernormal profit to fund R&D; innovations immediately copied by rivals with no IP protection). Perfect competition maximises static efficiency but may underperform on dynamic efficiency.

Monopolistic Competition

A market structure with: (1) Many firms. (2) Differentiated products — each firm's product is slightly different (different brand, design, location, quality). (3) Low barriers to entry and exit. (4) Each firm has some market power (faces downward-sloping demand curve) due to product differentiation — but limited by close substitutes. EXAMPLES: Restaurants, hairdressers, clothing retailers, petrol stations, coffee shops. The most common market structure in the real world.

Monopolistic Competition — Short Run

In the short run, a monopolistically competitive firm can earn supernormal profit (if successful differentiation). DIAGRAM: Draw downward-sloping D = AR curve and steeper MR curve. Draw U-shaped MC and ATC. Profit-maximising output: MC = MR → output Qsr. Price: read off demand curve at Qsr → Psr. If Psr > ATC at Qsr: supernormal profit rectangle. Label clearly.

Monopolistic Competition — Long Run

Supernormal profits attract new entrants (low barriers). New firms offer similar differentiated products → demand for each existing firm's product DECREASES (D shifts left) AND becomes MORE ELASTIC (more substitutes available). Entry continues until: D curve is tangent to ATC → P = ATC → normal profit only. Long run equilibrium: MC = MR (profit max) and P = ATC (normal profit). BUT: P > MC (allocative inefficiency) and P > minimum ATC (productive inefficiency — excess capacity).

DIAGRAM — Monopolistic Competition Long Run

Draw downward-sloping D (tangent to ATC at equilibrium). Draw MR (steeper, below D). Draw MC and ATC. Profit-maximising output Qlr: MC = MR. Price Plr: read off D at Qlr. At Qlr: D is tangent to ATC → Plr = ATC → normal profit. KEY FEATURES: (1) Plr > MC → allocative inefficiency (gap between D and MC). (2) Plr > minimum ATC → productive inefficiency (firm operates to left of minimum ATC). (3) Excess capacity = Q_min ATC − Qlr (the firm could produce more at lower unit cost but doesn't).

Excess Capacity in Monopolistic Competition

The difference between the output at minimum ATC (most productively efficient output) and the firm's actual long-run equilibrium output. Because the demand curve slopes downward and is tangent to ATC above its minimum: the firm produces LESS than the output that minimises ATC → it has excess (unused) capacity. This is the efficiency cost of product differentiation — society gets variety but pays a price in the form of higher costs than necessary. EXAMPLE: A town may have 20 coffee shops all operating below capacity rather than 5 highly efficient ones.

Non-Price Competition in Monopolistic Competition

Because products are differentiated and firms have some price-setting power, competition occurs through NON-PRICE means: (1) Product differentiation — design, quality, features, branding. (2) Advertising — build brand awareness and loyalty, reduce PED (make demand more inelastic). (3) Customer service — loyalty programmes, after-sales service. (4) Location — convenience for consumers. Non-price competition allows firms to maintain price above MC without immediately losing all customers. It is the primary competitive tool in monopolistic competition.

Oligopoly

A market structure dominated by a SMALL NUMBER OF LARGE FIRMS (though there is no precise number — typically 3–10 dominant firms). Key features: (1) Few firms, each with significant market share. (2) HIGH BARRIERS TO ENTRY — economies of scale, brand loyalty, capital requirements, etc. (3) Interdependence — each firm's decisions about price and output affect rivals → firms must consider rivals' reactions (strategic behaviour). (4) Products may be homogeneous (oil, steel) or differentiated (cars, smartphones, cereals). EXAMPLES: Global airline market, smartphone duopoly (Apple/Samsung), European supermarket sector, oil industry (OPEC), soft drinks (Coca-Cola/Pepsi).

Interdependence in Oligopoly

The defining feature of oligopoly: each firm's decisions (on price, output, advertising, product launches) directly affect its rivals and provoke reactions. This makes decision-making complex — a firm must anticipate how rivals will respond. EXAMPLE: If British Airways cuts fares, Ryanair and EasyJet will respond. BA must consider these reactions before deciding on its pricing strategy. This interdependence is why oligopoly behaviour cannot be explained by a single model — different models (kinked demand, game theory, collusion) capture different aspects.

Collusion

An agreement (explicit or tacit) between oligopolistic firms to coordinate their behaviour — typically to fix prices, limit output, or divide markets — in order to act collectively like a monopoly and earn supernormal profits. FORMAL (EXPLICIT) COLLUSION: direct communication and agreement (e.g. OPEC oil production agreements). TACIT COLLUSION: firms coordinate without explicit agreement — by following an industry price leader or signalling through public statements. Both forms are illegal under competition law in most countries (EU competition law, US Sherman Antitrust Act).

Cartel

A formal agreement between firms in an oligopolistic industry to coordinate output, prices, or market division in order to maximise collective profits — acting as a joint monopoly. EXAMPLE: OPEC (Organisation of Petroleum Exporting Countries) — member countries agree production quotas to control global oil prices. De Beers (historically controlled diamond supply). The Lysine cartel (US, exposed 1996). Cartels are illegal in most jurisdictions. They are inherently unstable because each member has an incentive to cheat (produce more than their quota and free ride on others' price restraint).

Why Cartels Are Unstable

Each cartel member has an individual incentive to CHEAT on the cartel agreement: by producing more than their quota, a firm can sell at the cartel price and increase its own profit — while the price impact is spread among all members. But if ALL members cheat → cartel collapses → output rises → price falls → all members worse off than under the cartel (but better off than if they alone had cheated while others restrained). This is the prisoner's dilemma structure. Cartels are also vulnerable to: new entrants (if barriers are not absolute), government detection and prosecution, economic downturns (members cheat to maintain revenue).

Game Theory

A branch of mathematics/economics that analyses strategic interactions — situations where each player's optimal decision depends on what they expect others to do. Central to understanding oligopoly behaviour. Key concepts: players, strategies, payoffs, dominant strategy, Nash equilibrium. Developed by John von Neumann and Oskar Morgenstern (1944); further developed by John Nash (Nash equilibrium, Nobel 1994).

Dominant Strategy

In game theory: a strategy that gives a player the highest payoff regardless of what the other player does. If a dominant strategy exists, a rational player will always choose it — they do not need to predict the rival's behaviour. EXAMPLE: In the prisoner's dilemma, confessing is a dominant strategy for each prisoner — confessing gives a better outcome regardless of what the other prisoner does.

Nash Equilibrium

A situation in game theory where no player can improve their payoff by unilaterally changing their strategy, given the strategies chosen by all other players. Each player is playing their best response to the other's strategy. EXAMPLE: In the prisoner's dilemma, (confess, confess) is the Nash equilibrium — neither prisoner can improve their outcome by changing their choice given what the other is doing. Nash equilibria may not be socially optimal — the prisoner's dilemma Nash equilibrium is worse for both players than (don't confess, don't confess).

Prisoner's Dilemma

A classic game theory model showing why rational individuals pursuing self-interest can produce outcomes that are collectively worse than cooperation. TWO PLAYERS: each can COOPERATE or DEFECT. If both cooperate: moderate reward for both. If both defect: poor outcome for both. If one defects and other cooperates: defector gets best outcome, cooperator gets worst. RESULT: Defect is the dominant strategy for both → Nash equilibrium = (Defect, Defect) → both get poor outcome, even though (Cooperate, Cooperate) would be better for both. APPLIED TO OLIGOPOLY: two firms can collude (cooperate) or compete (defect). Each has incentive to undercut the other → collude/collude is unstable → Nash equilibrium may be compete/compete → cartel breaks down.

Prisoner's Dilemma — Payoff Matrix

Draw a 2×2 matrix. Rows = Firm A's strategies (Collude/Compete). Columns = Firm B's strategies (Collude/Compete). Four cells show payoffs (Firm A profit, Firm B profit): EXAMPLE NUMBERS: (Collude/Collude): (€10m, €10m). (Collude/Compete): (€2m, €15m). (Compete/Collude): (€15m, €2m). (Compete/Compete): (€6m, €6m). Dominant strategy: Compete (€15m > €10m if B colludes; €6m > €2m if B competes). Nash equilibrium: (Compete, Compete) → €6m each. Collude/Collude (€10m each) is better for both but is not a Nash equilibrium — each has incentive to deviate.

Kinked Demand Curve Model (Sweezy Model)

A model of oligopoly price rigidity developed by Paul Sweezy (1939). Assumption: if a firm RAISES its price, rivals will NOT follow (they gain market share by keeping prices lower) → demand for the price-raiser is elastic above current price. If a firm LOWERS its price, rivals WILL follow (to avoid losing market share) → demand is inelastic below current price. Result: the demand curve has a KINK at the current price → demand is elastic above and inelastic below the kink → MR curve has a VERTICAL GAP (discontinuity) at the kink quantity. Firms are reluctant to change prices → price rigidity/stickiness in oligopoly.

DIAGRAM — Kinked Demand Curve

Draw axes (P, Q). Mark current price P* and quantity Q* on the axes. Draw a relatively elastic demand curve from the Y-axis down to the kink at (Q, P) — label this segment "d1 (elastic — rivals don't follow price rise)." From the kink, draw a steeper (inelastic) demand curve continuing downward to the X-axis — label "d2 (inelastic — rivals follow price cuts)." The combined kinked demand curve = D. Draw the corresponding MR curve: has a vertical gap (discontinuity) at Q. Draw MC curve passing through the vertical gap of MR — profit max still at Q, P* even if MC shifts within the gap → price remains P* (explains price rigidity). Label all elements.

Price Leadership

A form of tacit collusion in oligopoly where one firm (the dominant firm or barometric firm) sets the price and others follow without explicit agreement. The price leader signals price changes (often through public announcements) and rivals adjust their prices accordingly. Legal (no explicit agreement) but achieves similar coordination to collusion. EXAMPLES: Saudi Arabia acts as price leader in OPEC. Historically, firms like US Steel, American Tobacco led pricing in their industries.

Non-Collusive Oligopoly

Oligopoly behaviour where firms compete independently without coordination. May result in: price wars (aggressive price competition that harms all firms), product differentiation competition (advertising, innovation), or kinked demand curve price stability. Non-collusive oligopoly is the outcome when collusion breaks down or is prevented by competition authorities.

Monopoly

A market structure with: (1) ONE firm — the sole producer in the market. (2) HIGH BARRIERS TO ENTRY — the monopolist is protected from competition. (3) The firm IS the industry — no distinction between firm and industry demand. (4) The firm is a PRICE MAKER — faces the downward-sloping market demand curve. (5) Unique product — no close substitutes. EXAMPLES: Natural monopolies (water supply, electricity grid, rail networks), patented pharmaceuticals, Google Search (~90% global market share), De Beers (historically in diamonds).

Natural Monopoly

A monopoly that arises because the nature of the industry means one firm can supply the entire market at lower cost than two or more firms. Characterised by: very high fixed costs (infrastructure), low marginal costs, and economies of scale so large that the ATC curve is still declining over the entire relevant range of output. EXAMPLES: Water supply networks, electricity transmission grids, railway tracks, natural gas pipelines. IMPLICATION: Competition would be inefficient (duplication of infrastructure) → natural monopolies are typically either nationalised or privately owned but regulated.

DIAGRAM — Natural Monopoly

Draw downward-sloping D = AR and steeper MR. Draw a downward-sloping ATC curve (declining over entire relevant demand range — never reaching minimum within the market) and MC curve below ATC (also declining, less steeply). Profit-maximising output: MC = MR → Qm. Price: read off demand at Qm → Pm. Since ATC is still falling at Qm: P > ATC at Qm → supernormal profit. The ATC is declining throughout → one firm can serve the market more cheaply than two. Label all curves and mark supernormal profit rectangle.

Monopoly — Profit Maximisation Diagram

Draw downward-sloping D = AR and steeper MR curve (same Y-intercept, twice the slope for linear demand). Draw U-shaped MC and ATC curves. Profit max: MC = MR → output Qm. Price: read up from Qm to demand curve → Pm (this is the monopoly price — above the competitive price). Check profit: if Pm > ATC at Qm → supernormal profit rectangle (Pm − ATC) × Qm shaded above ATC. DWL compared to perfect competition: triangle between Qm and Qpc (competitive output where D = MC), bounded by demand above and MC below. Label all: Qm, Pm, ATC at Qm, supernormal profit, DWL.

Monopoly vs Perfect Competition — Welfare Comparison

PERFECT COMPETITION equilibrium: P = MC = minimum ATC. Output = Qpc. Maximum total surplus — no DWL. MONOPOLY equilibrium: P > MC (P = Pm > MC at Qm). Output = Qm < Qpc. Pm > Ppc. Monopoly REDUCES output and RAISES price compared to perfect competition → welfare loss. DIAGRAM: On same axes, show competitive equilibrium at (Ppc, Qpc) where D intersects MC. Monopoly output Qm (where MR = MC). Monopoly price Pm (on demand curve). DWL = triangle between Qm and Qpc, bounded by D above and MC below. Transfer from consumer to producer surplus = rectangle between Pm and Ppc up to Qm.

Price Discrimination

When a firm charges different prices to different consumers (or groups of consumers) for the same good or service, for reasons NOT related to differences in cost. Requires: (1) Market power (price maker). (2) Ability to identify and separate different consumer groups with different PED. (3) Ability to prevent resale between groups (arbitrage). Three degrees: 1st degree (perfect), 2nd degree (by quantity), 3rd degree (by group).

First Degree Price Discrimination (Perfect)

Each unit is sold at the maximum price each individual consumer is willing to pay. Producer captures ALL consumer surplus — CS = 0, PS = maximum possible. Output = competitive output (same as P = MC — allocatively efficient). No DWL — all mutually beneficial transactions occur. Theoretical extreme — requires perfect information about every consumer's willingness to pay. APPROXIMATED BY: personalised pricing algorithms (Amazon, airlines), negotiated prices (car dealerships, salary negotiations), auctions.

Second Degree Price Discrimination

Different prices charged based on the QUANTITY purchased — not the identity of the buyer. All buyers face the same price schedule but pay different amounts based on how much they buy. EXAMPLES: (1) Block pricing — first 100 units at €10, next 100 at €8, next 100 at €6 (utility companies). (2) Bulk discounts — buying in larger quantities gets a lower per-unit price (Costco, wholesale clubs). (3) Two-part tariff — fixed entry fee + per-unit price (gym memberships, amusement parks, Amazon Prime + individual purchase prices).

Third Degree Price Discrimination

Different prices charged to different identifiable GROUPS of consumers based on their different price elasticities of demand. The group with MORE INELASTIC demand is charged a HIGHER price; the group with MORE ELASTIC demand is charged a LOWER price. EXAMPLES: Student/senior discounts (students and seniors have more elastic demand — more price sensitive). Peak vs off-peak rail fares (commuters inelastic, leisure travellers elastic). Business vs economy class airfares. Geographic price discrimination (same drug priced differently in USA vs India). Condition for profit max: MR must be equal across all groups (and = MC).

Third Degree Price Discrimination — Diagram

Draw TWO separate demand diagrams (one per group). GROUP 1 (inelastic demand): steeper D1 and corresponding MR1. GROUP 2 (elastic demand): flatter D2 and corresponding MR2. Profit max condition: MR1 = MR2 = MC. From each MR = MC intersection, read off the profit-maximising quantity for each group (Q1, Q2). Read price from each group's demand curve (P1 > P2, since group 1 has more inelastic demand). The firm charges P1 to group 1 and P2 to group 2. Total profit = (P1 − ATC)×Q1 + (P2 − ATC)×Q2.

Conditions for Price Discrimination

(1) MARKET POWER — the firm must be a price maker (face downward-sloping demand). A perfectly competitive firm cannot price discriminate — it is a price taker. (2) ABILITY TO SEGMENT THE MARKET — identify different groups with different PED (e.g. students vs adults, business vs leisure travellers). (3) PREVENTION OF ARBITRAGE (RESALE) — consumers in the low-price group must not be able to resell to consumers in the high-price group (otherwise price differences collapse). EXAMPLE: Airlines prevent resale by making tickets non-transferable and linked to passport ID.

Welfare Effects of Price Discrimination

COMPARED TO SINGLE-PRICE MONOPOLY: (1) Output is higher under price discrimination (approaches competitive output in 1st degree). (2) More consumers are served. (3) Consumer surplus is REDUCED (transferred to producer). (4) Total surplus may INCREASE (less DWL) or stay the same depending on degree. FIRST DEGREE: CS = 0, PS = maximum, DWL = 0 → efficient but extremely inequitable. THIRD DEGREE: ambiguous welfare effects — increases output and reduces DWL compared to single-price monopoly, but distributional effects are regressive if lower-income groups pay more.

Government Intervention Against Monopoly Power

(1) COMPETITION POLICY (ANTITRUST) — laws preventing abuse of market power, blocking anticompetitive mergers, prohibiting cartels. EXAMPLE: EU Competition Commission blocked Google Shopping (€2.4bn fine 2017), Facebook/Instagram merger scrutiny. (2) REGULATION — for natural monopolies: regulate price (price cap regulation: RPI − X formula) or rate of return regulation. (3) NATIONALISATION — government takes ownership of natural monopolies (water, rail) to ensure public interest pricing. (4) BREAKING UP MONOPOLIES — forced divestiture (e.g. Standard Oil broken up 1911, AT&T 1984). (5) TRADE LIBERALISATION — opening markets to foreign competition reduces domestic market power.

Price Cap Regulation (RPI − X)

A regulatory approach for natural monopolies. The regulator sets a maximum price equal to the Retail Price Index minus an efficiency factor X. The firm can raise prices by at most (inflation − X)% per year. The X factor is set based on expected productivity improvements the firm should achieve. ADVANTAGE: gives the firm an incentive to reduce costs (can keep the savings if costs fall faster than X requires). EXAMPLE: Ofwat (UK water regulator) uses RPI − X price caps for water companies. Evaluated as superior to rate-of-return regulation (which gives no cost reduction incentive).

Oligopoly — Efficiency Assessment

PRODUCTIVE EFFICIENCY: oligopolies typically do NOT produce at minimum ATC (P > min ATC) — productively inefficient. ALLOCATIVE EFFICIENCY: P > MC → allocatively inefficient. DYNAMIC EFFICIENCY: oligopolies may be DYNAMICALLY EFFICIENT — supernormal profits fund significant R&D and innovation (pharmaceutical industry, technology sector). Schumpeter argued large firms with market power are the primary source of innovation (creative destruction). Trade-off: static inefficiency vs dynamic efficiency — a key evaluative point in essays on market power.

Monopoly — Efficiency Assessment

PRODUCTIVE EFFICIENCY: monopoly typically produces to the left of minimum ATC → productively inefficient (though natural monopolies may have declining ATC throughout). ALLOCATIVE EFFICIENCY: P > MC → allocatively inefficient → DWL compared to competitive outcome. DYNAMIC EFFICIENCY: monopoly has mixed record — large profits may fund R&D (pharmaceutical patents incentivise drug development) but absence of competitive pressure may reduce innovation incentive. X-INEFFICIENCY (Leibenstein): without competitive pressure, monopolists may not minimise costs — managers pursue quiet life, allow slack → costs higher than necessary. Overall: monopoly is the least efficient market structure in static terms.

X-Inefficiency

The tendency for firms with market power (especially monopolies) to be less efficient than they could be, because the absence of competitive pressure reduces the incentive to minimise costs. Identified by Harvey Leibenstein (1966). Without fear of losing customers to rivals, managers may pursue personal objectives (comfortable working conditions, excessive perks, empire-building) rather than cost minimisation. EXAMPLE: State-owned monopolies often cited for X-inefficiency — bloated bureaucracies, overstaffing, resistance to technological change. Privatisation and introducing competition are responses.

Creative Destruction (Schumpeter)

Joseph Schumpeter's theory that capitalism progresses through waves of innovation where new technologies and business models destroy old industries and create new ones. Large firms and monopolies are the primary drivers of this process — they have the resources and market power to invest in transformative R&D. EXAMPLE: Amazon destroyed traditional retail; Netflix destroyed video rental; smartphones destroyed digital cameras and GPS devices. Schumpeter argued that the dynamic efficiency of large innovative firms outweighs their static inefficiencies (DWL, P > MC). This is a key argument in the evaluation of monopoly and oligopoly power.

Government Intervention Against Oligopoly

(1) COMPETITION LAW — prohibit explicit collusion and cartels (EU Article 101 TFEU; US Sherman Act Section 1). (2) MERGER CONTROL — competition authorities review mergers that may create or strengthen market dominance. EXAMPLE: EU blocked the Siemens/Alstom rail merger (2019) to protect competition. (3) PROHIBITION OF PREDATORY PRICING — illegal to price below cost with intent to drive out rivals. (4) REGULATION OF DOMINANT FIRMS — prevent abuse of dominant position (EU Article 102; US Sherman Act Section 2). (5) BEHAVIOURAL REMEDIES — require firms to change business practices (e.g. Google required to show rival search engines in EU).

Real World Example — Monopoly (Pharmaceutical Industry)

Pharmaceutical companies hold patents giving them monopoly rights for 20 years on new drugs. This allows pricing far above MC. EXAMPLE: Daraprim (toxoplasmosis drug) — price raised from $13.50 to $750 per pill overnight by Turing Pharmaceuticals (2015) after acquiring the patent — classic monopoly pricing. Justification: patent monopoly profits incentivise the massive R&D investment required to develop new drugs (~$2.6 billion average cost per approved drug). Trade-off: static inefficiency (high prices, underconsumption, DWL) vs dynamic efficiency (innovation incentive). After patent expiry, generic entry drives prices toward MC — illustrating competitive market efficiency.

Real World Example — Oligopoly (Global Smartphone Market)

The smartphone market is a duopoly (Apple and Samsung) by revenue, with Xiaomi, OPPO, and others competing at lower price points. Features of oligopoly: HIGH BARRIERS TO ENTRY (massive R&D costs, brand loyalty, app ecosystems, component supply chains). INTERDEPENDENCE: Apple's iPhone release directly affects Samsung's strategy and vice versa. NON-PRICE COMPETITION: both firms invest billions in R&D, design, camera technology, operating system ecosystems. PRODUCT DIFFERENTIATION: iOS vs Android ecosystems create switching costs (barriers to consumer switching) that give each firm loyal customer base with inelastic demand. DYNAMIC EFFICIENCY: fierce competition drives rapid innovation (new features every year). This market combines oligopolistic market power with intense innovation — illustrating the Schumpeterian argument that imperfect competition can drive dynamic efficiency.

Real World Example — Price Discrimination (Airlines)

Airlines are the classic example of third-degree price discrimination. Same seat on same flight priced differently based on: booking timing (early bookers vs last minute), flexibility (refundable vs non-refundable), travel class (economy/business/first), loyalty status, route (business routes command premium). MECHANISM: airlines use sophisticated yield management algorithms to identify each consumer's maximum willingness to pay. Conditions met: market power on specific routes (especially where one airline dominates), market segmentation (business vs leisure travellers have very different PED), prevention of resale (tickets non-transferable). WELFARE EFFECTS: compared to single-price monopoly — more seats filled (higher output), some consumers pay less (leisure travellers), some pay much more (business travellers). Airlines capture large share of consumer surplus.

Real World Example — Natural Monopoly (Rail Network, Austria)

ÖBB (Österreichische Bundesbahnen) operates Austria's rail network. The rail track infrastructure is a natural monopoly — duplicating the track would be massively inefficient (enormous fixed costs, economies of scale mean one operator can serve all demand at lower ATC than two). ÖBB is state-owned — the government directly provides the service rather than allowing private monopoly. The rail network also has significant positive externalities (reduces road congestion, carbon emissions from cars). Nationalisation allows: pricing decisions based on social welfare (subsidised fares for students, seniors, commuters), investment in public interest (rural connections that would be unprofitable for private firm), integration with urban transport systems. Trade-off: potential X-inefficiency from lack of competitive pressure.

Profit Maximisation — Is It Always the Firm's Objective?

Standard economic theory assumes profit maximisation but real firms may pursue alternative objectives: (1) SALES MAXIMISATION (Baumol) — maximise revenue (TR), subject to making at least normal profit. Produces more than profit-maximising output at a lower price. (2) GROWTH MAXIMISATION — managers seek to expand firm size (empire building). (3) SATISFICING (Simon) — achieve a satisfactory (not maximum) profit level. (4) SOCIAL/ENVIRONMENTAL OBJECTIVES — some firms (B-corps, social enterprises, cooperatives) explicitly prioritise social or environmental goals alongside profit. (5) MANAGER VS OWNER OBJECTIVES (principal-agent problem) — managers (agents) may pursue personal objectives different from owners' (principals') profit maximisation goal. These alternative objectives affect market outcomes and efficiency.

Chapter 7 — Key Comparisons Table

PERFECT COMPETITION: Many firms, homogeneous product, no barriers, P = MC = min ATC (LR), normal profit (LR), productively + allocatively efficient, no market power. MONOPOLISTIC COMPETITION: Many firms, differentiated, low barriers, P > MC, P = ATC (LR), normal profit (LR), excess capacity, some market power. OLIGOPOLY: Few firms, homogeneous or differentiated, high barriers, P > MC, supernormal profit possible (LR), interdependence, game theory, high market power. MONOPOLY: One firm, unique product, very high barriers, P > MC >> min ATC, supernormal profit (LR), DWL, maximum market power.