Economies and diseconomies of scale: internal and external

1. Meaning

Economies of scale are the advantages, in the form of lower cost per unit, that a firm gains when it expands its scale of production. Diseconomies of scale are the disadvantages, in the form of rising cost per unit, that appear when the firm grows beyond its optimum size. Economies explain increasing returns to scale and the falling part of the long-run average cost curve; diseconomies explain diminishing returns and its rising part.

The classification into internal and external economies is Marshall’s, in Principles of Economics (1890).

• Internal economies arise inside the firm from its own expansion. They are open to that firm alone and depend on its own decisions.
• External economies arise outside the firm from the growth of the whole industry or of the region. They are shared by all firms in the industry.

2. Internal economies

1. Technical economies. The most important. A large firm can use large, specialised and more efficient machines that a small firm cannot keep fully busy (indivisibility); it can link processes (a steel plant using its own waste heat); it can use superior techniques and continuous processes; it can use by-products.
2. Managerial economies. Division of managerial work into specialised departments (production, finance, marketing, personnel) run by experts; delegation of routine work; use of computers and modern methods of control.
3. Marketing (commercial) economies. Bulk purchase of raw materials at discounts and on better credit; lower cost of advertising per unit sold; its own sales network and transport; a known brand.
4. Financial economies. A large firm borrows more cheaply and easily from banks, raises capital in the market by issuing shares and debentures, and is trusted by investors.
5. Risk-bearing economies. Spreading risk through diversification of output (many products), of markets (many regions and countries) and of sources of supply.
6. Research and development economies. A large firm can afford laboratories and research staff, leading to new products and lower costs.
7. Labour economies. Specialisation of workers, in-house training, and welfare facilities that attract and keep better workers.
8. Transport and storage economies. Own fleet, own warehouses, lower cost per unit carried or stored.

3. External economies

1. Economies of concentration (localisation). When many firms of one industry gather in one place, the region develops roads, power, banks, skilled labour and repair services that all firms use: textile mills around Coimbatore, software firms in Bengaluru.
2. Economies of information. Trade journals, research institutes and industry associations spread knowledge that every firm can use.
3. Economies of disintegration (specialisation). As the industry grows, separate firms specialise in one process or one component (dyeing, spare parts), supplying others more cheaply than each could do for itself.
4. Economies of by-products. Waste of one firm becomes the raw material of another (molasses from sugar mills for distilleries).
5. Government and infrastructure support. Industrial estates, export zones and training institutes set up for a growing industry.

4. Diseconomies of scale

Internal diseconomies.

• Managerial diseconomies: beyond a point, management becomes unwieldy. Layers of hierarchy slow decisions, communication breaks down, coordination and supervision weaken, and red tape grows. This is the chief cause.
• Technical diseconomies: machines larger than the optimum, or plants too big to run smoothly; a breakdown in one part halts the whole.
• Labour diseconomies: loss of personal contact between management and workers, leading to disputes, strikes and low morale.
• Marketing diseconomies: to sell a very large output the firm must spend heavily on advertising or cut prices.
• Financial diseconomies: heavy borrowing raises the rate of interest and the risk of insolvency.
• Risk diseconomies: a mistake in a large firm causes large losses.

External diseconomies. When an industry concentrates too much in one area: rising rents and land prices, shortage and higher wages of skilled labour, congestion of transport, shortage of raw materials and power, pollution and the cost of controlling it.

5. Advantages and disadvantages of large-scale production

The Kannada version of the January 2026 question asks for the advantages and disadvantages of large-scale production. The advantages are the economies above, which reach the consumer as lower prices and better quality and the economy as more output, exports and research. The disadvantages are the diseconomies, together with social costs: concentration of economic power and the risk of monopoly, loss of the personal touch, industrial unrest, regional imbalance, and pollution. Concentration of economic power is why the Competition Act, 2002 regulates combinations above the notified thresholds and abuse of dominant position.

6. Optimum firm

The firm whose scale gives the lowest long-run average cost is the optimum firm. Up to that size economies outweigh diseconomies; beyond it, diseconomies dominate. E.A.G. Robinson’s The Structure of Competitive Industry (1931) analysed the forces (technical, managerial, financial, marketing, risk) that each set an optimum size, and the firm’s actual optimum is a compromise among them.

How this is examined

January 2026: “Explain economies of scale” (10 marks). August 2024: “Diseconomies of scale” (6 marks). For the essay, define, give Marshall’s twofold classification, explain five or six internal and three or four external economies with Indian examples, and close with the diseconomies and the optimum firm. For the short note on diseconomies, give internal and external with two lines each.