Monopoly & Monopolistic Competition

Monopoly & Monopolistic Competition

Monopoly and monopolistic competition represent market structures with less competition than perfect competition. Understanding their characteristics, behaviour, and welfare implications is essential for A-Level evaluation.

Pure Monopoly

A pure monopoly exists when a single firm is the sole supplier of a product with no close substitutes. In UK competition law, a firm with 25% or more market share is considered to have monopoly power.

Characteristics

• Single seller: one firm dominates the market
• High barriers to entry: prevent new firms from competing away supernormal profit
• Unique product: no close substitutes
• Price maker: the firm sets price (faces the entire market demand curve)
• Imperfect information: consumers may lack alternatives

Barriers to Entry

Type	Example
Economies of scale	Natural monopoly (water, rail) — one firm can supply at lower cost
Legal/regulatory	Patents (pharmaceuticals), licences (broadcasting), copyright
Brand loyalty	Decades of advertising (Coca-Cola)
Control of resources	De Beers (historically) controlling diamond supply
Predatory pricing	Cutting prices below cost to drive out entrants
Sunk costs	Heavy upfront investment deters entry (aircraft manufacturing)
Network effects	Value increases with users (Meta, Microsoft) — creates lock-in

Monopoly Revenue and Output

The monopolist faces a downward-sloping demand curve (AR curve). To sell more, it must lower the price on all units.

• MR < AR at all output levels (MR curve lies below AR)
• MR falls twice as steeply as AR (for a linear demand curve)
• TR is maximised where MR = 0

Profit Maximisation

The monopolist maximises profit where MC = MR:

• Price is read from the demand (AR) curve at the profit-maximising output
• If AR > ATC, the firm earns supernormal profit = (AR - ATC) × Q
• These profits can be sustained in the long run because barriers to entry prevent competition

Price Discrimination

A monopolist with market power may practise price discrimination — charging different prices to different consumers for the same product where the price difference does not reflect cost differences.

Conditions required:

1. Market power (price maker)

2. Ability to separate markets (prevent resale/arbitrage)

3. Different PED in each market segment

Types:

• First degree (perfect): each consumer charged their maximum willingness to pay (consumer surplus = 0). Rare but approximated by auctions, personalised pricing.
• Second degree: different prices for different quantities (bulk discounts, off-peak pricing)
• Third degree: different prices for different groups (student discounts, peak/off-peak rail, international pricing)

Evaluation of price discrimination:

• May increase output (and employment) compared to single-price monopoly
• Can cross-subsidise loss-making services (rural rail routes funded by profitable ones)
• Reduces consumer surplus and may be seen as unfair
• Can increase allocative efficiency if output rises towards the competitive level

Efficiency and Welfare in Monopoly

Allocative Inefficiency

Monopoly produces where P > MC: consumers value the last unit more than it costs to produce, but the monopolist restricts output to raise price. This creates a deadweight loss (welfare loss triangle).

Productive Inefficiency

Monopolists do not necessarily produce at the minimum ATC. Lack of competitive pressure may lead to X-inefficiency (Leibenstein) — organisational slack, overstaffing, and waste.

Dynamic Efficiency: The Case FOR Monopoly

Schumpeter argued monopoly profits:

• Fund R&D and innovation (pharmaceutical companies invest billions in drug development, protected by patents)
• Enable risk-taking on long-term projects
• Provide incentive to innovate (the prospect of monopoly profit drives "creative destruction")

Counter-argument: without competitive pressure, monopolists may have less incentive to innovate (the "quiet life" hypothesis).

Natural Monopoly

A natural monopoly exists where the MES is so large relative to market demand that one firm can supply the entire market at lower cost than two or more firms.

• The LRAC is still falling at the level of market demand
• Examples: water pipes, electricity grid, railway tracks
• Duplication of infrastructure would be wasteful
• Often subject to government regulation (Ofwat, Ofgem)

Government Responses to Monopoly

Policy	How It Works	Evaluation
Price regulation	Cap prices (e.g., RPI - X)	Encourages efficiency but may discourage investment if returns are too low
Profit regulation	Limit rate of return	May lead to gold-plating (over-investing to inflate the cost base)
Breaking up monopolies	Forced divestiture	May sacrifice economies of scale
Nationalisation	State ownership	Public interest focus but may lack efficiency incentives
Contestability	Reduce barriers to entry	Threat of entry disciplines monopolist behaviour
Competition policy	CMA investigations, blocking mergers	Prevention may be more effective than cure

Monopolistic Competition

Monopolistic competition lies between perfect competition and monopoly on the spectrum of market structures.

Characteristics

• Many firms: each with a small market share
• Product differentiation: goods are similar but not identical (branding, quality, design, location)
• Low barriers to entry and exit: relatively easy for new firms to join
• Some price-making power: firms face a downward-sloping demand curve, but it is relatively elastic (many substitutes)
• Non-price competition: advertising, branding, quality, customer service

Short-Run Equilibrium

• Firm maximises profit where MC = MR
• If AR > ATC: supernormal profit
• This attracts new entrants

Long-Run Equilibrium

• Entry of new firms shifts each existing firm's demand curve left (market share falls)
• Entry continues until supernormal profit is competed away
• Long-run equilibrium: AR = ATC (tangency point) — normal profit only
• But unlike perfect competition, AR = ATC does not occur at minimum ATC

Efficiency in Monopolistic Competition

Allocatively inefficient: P > MC (firms have some market power)

Productively inefficient: not at minimum ATC. Firms produce on the downward-sloping section of ATC — there is excess capacity. Each firm could produce more at lower average cost but chooses not to because it would require cutting price below ATC.

However:

• Product differentiation gives consumers variety and choice
• Non-price competition drives quality improvements
• This may outweigh the static efficiency losses
• Dynamic efficiency may be moderate (incentive to innovate to differentiate)

Real-World Examples

• Restaurants and cafes
• Hairdressers and beauty salons
• Clothing retailers
• Independent coffee shops

Evaluation: Comparing Market Structures

Criterion	Perfect Comp.	Monopolistic Comp.	Monopoly
Allocative efficiency	Yes	No	No
Productive efficiency	Yes (LR)	No	Not necessarily
Dynamic efficiency	Low	Moderate	Potentially high
Consumer choice	None (homogeneous)	High (variety)	One product
Long-run supernormal profit	No	No	Yes

Exam Technique

• For monopoly diagrams: always show MC = MR (output), then read price from AR, and shade supernormal profit area (AR - ATC) × Q
• Compare monopoly with perfect competition explicitly: higher price, lower output, deadweight loss
• Evaluate using Schumpeter (dynamic efficiency) as the key counter-argument to static inefficiency
• For monopolistic competition, emphasise the tangency condition in long-run equilibrium