Economies and diseconomies of scale

1. Meaning

Economies of scale are the advantages, in the form of lower cost per unit, that a firm or an industry enjoys as the scale of production expands. As output grows, average cost falls. They are the main cause of increasing returns to scale.

Alfred Marshall, in Principles of Economics, divided them into two kinds:

• Internal economies: those open to a single firm as a result of its own expansion, independent of other firms. They arise inside the firm and depend on its own size, organisation and management.
• External economies: those open to all firms in an industry as a result of the growth of the industry as a whole, usually in a particular area. No single firm controls them.

2. Internal economies

1. Technical economies. A large firm can use bigger and more efficient machines, which a small firm cannot keep fully employed (the indivisibility of capital). It can link processes (a steel plant using its own waste heat), use by-products (a sugar mill selling molasses and bagasse), and adopt superior techniques. Technical economies are usually the most important.
2. Managerial economies. A large firm can divide management into specialised departments (production, finance, marketing, personnel) headed by experts, and delegate routine work. The cost of management per unit falls.
3. Marketing or commercial economies. Bulk buying of raw materials at a discount and on better credit terms; lower transport cost per unit; advertising spread over a large output; its own sales network.
4. Financial economies. A large, well-known firm can raise capital more cheaply and easily: banks lend to it at lower interest, and it can issue shares and debentures to the public.
5. Risk-bearing economies. A large firm can spread risk by diversifying its output (producing several products), its markets and its sources of supply, so that a loss in one line is offset by gains in another.
6. Labour economies. Finer division of labour and specialisation raise efficiency; the firm can attract skilled workers with better pay.
7. Research and development economies. Only a large firm can afford its own laboratories and research staff.
8. Welfare economies. Housing, canteens, hospitals and schools for workers, which raise morale and productivity.

3. External economies

1. Economies of concentration (localisation). When an industry concentrates in one region, all firms benefit from a pool of skilled labour, better transport and power, banking and insurance facilities, and nearby suppliers. Examples: cotton textiles around Mumbai and Ahmedabad, software in Bengaluru.
2. Economies of information. Trade journals, research institutes and industry associations share technical and market information with all firms.
3. Economies of disintegration (specialisation). As an industry grows, some processes are split off into specialised firms: one firm makes components, another dyes cloth, another repairs machines. Each firm can then concentrate on what it does best.
4. Economies of by-products. Separate firms come up to use the waste of the main industry.
5. Infrastructure economies. The government and others build roads, ports, training institutes and power lines in response to the growth of the industry.

4. Diseconomies of scale

Beyond a point, expansion raises cost per unit.

Internal diseconomies.

• Managerial difficulties: coordination and supervision become hard; decisions are delayed; red tape grows. This is the main reason for diminishing returns to scale.
• Labour problems: loss of personal contact between employer and workers, leading to disputes.
• Technical limits: a plant can be enlarged only so far before breakdowns become costly.
• Financial and marketing limits: capital becomes harder to raise and the market may not absorb more output without price cuts.
• Risk: a wrong decision in a giant firm causes large losses.

External diseconomies. Over-concentration of industry in one area raises rents and wages, causes congestion and shortage of power and water, and leads to pollution and higher transport costs.

5. Effect on cost curves

In the diagram of long-run average cost (output on the horizontal axis, cost on the vertical), economies of scale make the LAC curve slope downward as output rises; at the optimum size the economies are exhausted and LAC is at its minimum; beyond it, diseconomies make LAC rise. This is why the LAC curve is U-shaped, though flatter than the short-run curves. External economies shift the whole cost curve of every firm in the industry downward; external diseconomies shift it upward.

6. Internal and external economies compared

How this is examined

“What is economies of scale? Explain the internal and external economies of scale” was a 16-mark question in January 2026 (100-mark paper), and “Briefly explain the economies of scale” a 10-mark essay in June 2025 (80-mark). For the 16-mark answer, give at least five internal and four external economies with Indian examples, and add a paragraph on diseconomies.