Diseconomies of Scale in a Nutshell
Diseconomies of scale occur when a business grows so large that its average cost per unit starts to rise. Causes include poor communication, weak coordination, loss of control, low motivation and bureaucracy inside the firm, and rising rents, wages and congestion outside it. This gives the long-run average cost curve its U shape.
Diseconomies of Scale Definition
Diseconomies of scale occur when a firm’s output rises and its average cost per unit rises too. Growth stops reducing costs and starts increasing them. They appear in the long run, when the firm can change all its factors of production, which is why the long-run average cost (LRAC) curve is U-shaped.
The bottom of the U is the minimum efficient scale (MES), the output at which average cost is lowest. Beyond it, extra growth makes the business less efficient. Short-run cost rises caused by overworking a fixed factory are a different idea, because they come from diminishing returns, not from size.
Causes are internal or external. Internal causes arise inside the firm: coordination problems, loss of control, rising overheads, communication breakdown, alienation and low motivation, and bureaucracy. External causes come from the industry or location: higher land and rent, competition for labour, congestion, scarce materials and tighter regulation. Examiners reward students who separate the two clearly.
Studying and Revising?
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Diseconomies of Scale Characteristics/Features
- Rising average cost: unit costs increase as output increases.
- Long-run concept: the firm is changing its whole scale, not just its output from a fixed plant.
- U-shaped LRAC: average cost falls, bottoms out at the minimum efficient scale, then rises.
- Internal causes: communication, coordination, control, motivation and bureaucracy problems.
- External causes: higher rents, wages, congestion and scarcer inputs as the whole industry or area grows.
- Not inevitable: good management, decentralisation and technology can delay the rise in costs.
Examples of Diseconomies of Scale
Tesco’s Fresh and Easy chain in the USA (2007 to 2013) expanded rapidly, but the company lost control of its new stores and closed them with large losses.
Kodak invented the digital camera in 1975, but its huge, bureaucratic structure was slow to act and it filed for bankruptcy protection in 2012.
Silicon Valley shows external diseconomies. Rents, wages and congestion rose so high that firms struggled to afford staff and offices there. Amazon’s “two-pizza team” rule, which keeps teams small enough to feed with two pizzas, is a deliberate attempt to avoid internal diseconomies.
Advantages & Disadvantages of Diseconomies of Scale
Advantages
Leaner structures
Recognising diseconomies pushes a firm to remove unnecessary layers of management. Decisions are made faster and overhead costs fall, so average cost comes down.
Decentralisation
Giving local managers authority lets the business respond quickly to local customers. Less time is lost waiting for head office approval, so efficiency improves.
Smaller teams
Splitting a business into small units, as Amazon does with two-pizza teams, improves communication. Staff know each other and problems are solved sooner, so waste falls.
Higher motivation
When staff feel part of a small team with clear goals, engagement rises. Productivity improves and labour turnover falls, which cuts recruitment costs.
Focus on core activities
A firm that sees costs rising may sell off weak divisions. Management attention returns to profitable products, which lifts overall margins.
Better investment choices
Knowing where the minimum efficient scale lies stops a firm expanding past the point where growth destroys value. Money is spent on improving quality or entering new markets instead.
Disadvantages
Coordination problems
A large firm has many departments and sites. Marketing may promise a product that operations cannot make in time, so resources are duplicated or wasted and deadlines slip.
Loss of control
Senior managers cannot watch every site, so quality or standards can slip without anyone noticing. A problem at one outlet can damage the reputation of the whole chain.
Rising overheads
Bigger firms need more head office staff, IT systems, offices and compliance teams. These overheads grow faster than output and push up average cost.
Communication breakdown
A message passes through many layers of management, and each can delay or distort it. Staff act on wrong or late information, so errors and rework follow.
Alienation and low motivation
Workers can feel like a small cog in a machine. Productivity falls, absence rises and labour turnover increases, so recruitment and training costs add to average cost.
Bureaucracy
Large firms rely on rules, forms and approvals. Decisions take longer, rivals launch products first and administrative costs add to overheads without adding output.
Spotting Diseconomies in Data: Technique and Worked Examples
Average cost = total cost ÷ output. Diseconomies are visible when average cost rises as output rises. Consider this table:
- 10,000 units cost £50,000, so average cost = £5.00
- 20,000 units cost £80,000, so average cost = £4.00
- 30,000 units cost £105,000, so average cost = £3.50
- 40,000 units cost £152,000, so average cost = £3.80
Average cost falls until 30,000 units (economies of scale), then rises (diseconomies of scale). The turning point at 30,000 units is the minimum efficient scale. Total cost rose in every row, so always compare average cost, not total cost.
To find the percentage rise in average cost, use (new − old) ÷ old × 100. From £3.50 to £3.80: £0.30 ÷ £3.50 × 100 = 8.6% (to one decimal place).
Common Mistakes
Confusing a rise in total cost with diseconomies, calling any cost increase a diseconomy of scale, and mixing up short-run diminishing returns with long-run diseconomies.
Memory Trick
“Can Clever Children Make Big Leaps?” gives the six internal causes: communication, coordination, control, motivation, bureaucracy and labour relations.
Evaluation link. Diseconomies are not inevitable. Many large firms remain efficient, so the question is always whether management can stay ahead of the problems that growth creates.
Evaluating the Usefulness of Diseconomies of Scale
Strong evaluation asks whether diseconomies really outweigh the benefits of scale, and what they depend on. A decisive judgement might read: “Diseconomies are a serious risk for firms that grow faster than their management systems, but they are avoidable in industries where technology and decentralised structures keep communication strong.”
Speed of growth
Rapid growth, especially through takeovers, strains systems and culture most. Organic growth gives managers time to adapt.
Management quality and structure
Delegation, small teams and good communication systems can postpone diseconomies. Poor management brings them forward.
Industry
In industries with a high MES, such as car making, firms can grow very large before costs rise. In services based on personal contact, diseconomies appear early.
Technology
Modern communication and data systems can reduce coordination problems, so larger firms can stay efficient for longer than in the past.
Studying and Revising?
Reading through these notes is a solid start, but the real gains come from practising exam-style questions and receiving specific feedback. Most students skip this step because writing answers without marking feels pointless. The AI Business Tutor solves that problem: submit a practice answer, receive feedback broken down by AO1 to AO4, then rewrite and watch your mark improve. You get 3 free credits to start, and lessons and multiple-choice questions are free.
Practice Exam-Style Multiple Choice Questions for Diseconomies of Scale
Q1 What happens to average cost when diseconomies of scale occur?
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Correct answer: B. Diseconomies mean the cost per unit increases as the firm grows.
Q2 Which is an internal cause of diseconomies of scale?
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Correct answer: C. Communication problems arise inside the firm; the others are external.
Q3 In the table, average cost is £3.50 at 30,000 units and £3.80 at 40,000 units. What does this show?
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Correct answer: B. Average cost rises beyond 30,000 units.
Q4 The lowest point of the LRAC curve is called:
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Correct answer: B. MES is the lowest output at which average cost is at its minimum.
Practice GCSE Exam-Style Questions for Diseconomies of Scale with a Case Study
Read the following case study, then answer the questions below.
Coastal Coffee is a café chain run by owner Tamsin Reed. In 2023 it had 5 cafés and sold 200,000 cups at a total cost of £360,000. By 2026 it had grown to 42 cafés and sold 1,800,000 cups at a total cost of £3,960,000. Labour turnover has risen from 15% to 38%, and a survey found that 61% of baristas felt disconnected from the company. Tamsin is considering two options: giving café managers more decision-making power, or closing 12 cafés.
- Calculate the average cost per cup in 2023 and in 2026.2 marks
- Explain one reason why Coastal Coffee may be suffering from diseconomies of scale.3 marks
- Analyse how high labour turnover could affect Coastal Coffee’s costs.6 marks
- Evaluate which option Tamsin should choose. You should use the information provided as well as your knowledge of business.12 marks
For question 1: 2023 is £360,000 ÷ 200,000 = £1.80 per cup. 2026 is £3,960,000 ÷ 1,800,000 = £2.20 per cup. Average cost has risen by £0.40, or about 22%.
For question 4, decentralising may fix motivation and communication while keeping the cafés open. Closing 12 cafés cuts overheads quickly but loses sales and jobs. Make a clear recommendation and say what it depends on.
Practice A-Level Exam-Style Questions for Diseconomies of Scale with a Case Study
Read the following case study, then answer the questions below.
Meridian Group plc employs 64,000 staff in 19 countries and has revenue of £8.4 billion. It runs 14 incompatible IT platforms, costing £46 million a year to maintain, and has nine layers of management between the chief executive and front-line staff. Employee engagement is 48%, compared with 67% at its rival Corvane. In the logistics division, 2024 volumes were 120 million deliveries at a total cost of £1,080 million, while 2026 volumes were 150 million deliveries at a total cost of £1,470 million. Wages in the East Midlands depots have risen 11%, and traffic congestion adds 40 minutes to each delivery route.
- Calculate the percentage change in the logistics division’s average cost per delivery between 2024 and 2026.3 marks
- Explain one internal and one external cause of diseconomies of scale at Meridian Group.4 marks
- Analyse how the nine layers of management could affect Meridian Group’s costs.9 marks
- To what extent is bureaucracy the main cause of Meridian Group’s rising costs?16 marks
- Evaluate whether large multinationals can ever avoid diseconomies of scale.20 marks
For question 1: 2024 average cost = £1,080m ÷ 120m = £9.00. 2026 average cost = £1,470m ÷ 150m = £9.80. Change = £0.80 ÷ £9.00 × 100 = 8.89%.
For question 2, internal causes include the 14 incompatible platforms and the nine layers of management. External causes include rising wages in the East Midlands and congestion.
For question 4, weigh bureaucracy against external factors such as wages and congestion, which Meridian cannot control. Judge which is most important and why.
For question 5 there is no case, so use your own examples such as Amazon’s small teams. Argue that technology, decentralisation and a strong culture can avoid diseconomies, but that rapid acquisitions and external costs can still push average cost up.
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