Analyzing the Size Structure of Firms in Industrial Growth

Why do some industries get dominated by a handful of giant corporations while others remain a patchwork of tiny workshops? The answer lies in the size structure of firms – the distribution of enterprises across different scales within an economy. Understanding this structure is central to industrial growth, because the size of firms shapes productivity, employment, innovation, and even how cities and regions develop. This post unpacks how firm sizes evolve over time, the long-running debate between small and large enterprises, and the major theories economists use to explain why firms grow to the sizes they do.

The trajectory of firm size
From household enterprises to workshops
From factories to large-scale firms
Small versus large firms
The case for small firms
The case for large firms
The Indian reservation experiment
Theories of firm size
Technology-based explanations
Transaction cost explanations
Political economy explanations
Bringing the theories together

The trajectory of firm size

Industrial production did not always happen in large factories. The journey from informal household work to sprawling industrial complexes is a story of changing technology, markets, and organisation. Tracing this trajectory helps explain why a modern economy contains firms of wildly different sizes operating side by side.

From household enterprises to workshops

The earliest form of production was the household enterprise, where families produced goods using simple tools, local raw materials, and their own labour. Spinning, weaving, pottery, metalwork, and food processing were all carried out at or near the home. These units had no clear separation between the household and the workplace, and output was largely meant for local consumption or barter.

As demand grew and skills specialised, production moved into workshops run by artisans and craftspeople. A master craftsman might employ a few apprentices and journeymen, creating the first real division of labour. Many traditional crafts in India – handloom textiles, brassware, leatherwork – still operate close to this workshop model, blending inherited skills with manual processes.

From factories to large-scale firms

The factory system marked a decisive break. By bringing many workers under one roof, using mechanised power, and organising tasks into specialised stages, factories achieved scales of output impossible in a workshop. In India, the legal definition of a factory itself reflects this shift: under the Factories Act of 1948, a factory generally means a unit with more than 10 workers using power, or more than 20 workers without power.

Over time, some factories expanded into large-scale firms – multi-plant corporations with thousands of employees, vertically integrated supply chains, and access to organised capital markets. Yet smaller units never disappeared. The result is the layered size structure we see today, where household units, small workshops, mid-sized factories, and corporate giants all coexist. Recent estimates put India’s MSME count at around 633.9 lakh, with over 99% classified as micro-enterprises – a striking reminder that the vast base of any economy is made up of very small firms.

Small versus large firms

One of the longest-running debates in industrial economics concerns whether economies are better served by many small firms or a few large ones. Both have genuine strengths and weaknesses, and the “right” balance depends on the goals being prioritised – efficiency, employment, innovation, or regional balance.

The case for small firms

Small enterprises are prized for their flexibility and employment intensity. They typically require low capital, make heavy use of local raw materials and labour, and can adapt quickly to changing market conditions. Because they are labour-intensive, they generate large amounts of employment per rupee invested. In India, small-scale industries are the second-largest source of employment after agriculture, supporting well over 100 million workers.

Small firms also serve broader social goals. They promote decentralisation of economic activity, support rural entrepreneurship, and help bridge regional imbalances by spreading industry beyond a few metropolitan hubs. Research on small firm growth finds that factors like exporting can boost expansion, especially for young firms and women-owned enterprises.

The case for large firms

Large firms bring advantages that small units struggle to match. They benefit from economies of scale, spreading fixed costs across high volumes of output and lowering per-unit costs. They can invest in advanced technology, formal research, quality control, and skilled management. They also have far better access to organised finance.

This matters because capital markets in developing economies are often fragmented, forcing firms to rely on their own internal funds for investment. Studies of Indian manufacturing find that internal funds are relatively more important for large firms producing higher-value goods – large firms can self-finance growth in ways small units cannot. On productivity, the evidence generally favours scale: while small firms enjoy flexible management and faster response times, larger firms tend to be more productive overall.

The Indian reservation experiment

India ran one of the world’s most ambitious experiments in deliberately favouring small firms. For decades, the government used a product reservation policy that set aside certain products for exclusive manufacture by small-scale units. Beginning with just 47 items, the reserved list eventually grew to over 1,000 products by 1996. Large firms were barred from entering these product lines or were capped at their existing output.

The policy had unintended consequences. By shielding small units from competition, it sometimes encouraged a proliferation of inefficient firms that could not achieve scale or modernise. One review of the small-scale sector argued that its unusually high growth came not from genuine efficiency or innovation but from a policy bias against largeness. When products were gradually de-reserved from the late 1990s onwards, researchers found measurable benefits: de-reservation was associated with more new product introductions and faster sales growth on average. Other studies documented gains in product quality and total factor productivity, with larger and more productive firms benefiting most once restrictions were lifted.

The lesson is nuanced. Protecting small firms can deliver employment and entrepreneurship, but artificially suppressing firm size can trap an economy in low productivity. The challenge is designing policy that supports small enterprises without penalising the ones that are ready to grow.

Theories of firm size

If firms naturally vary in size, what determines how big any individual firm becomes? Economists have offered several distinct explanations. The main perspectives are technology-based, transaction cost, and political economy approaches – each highlighting a different driver of firm size dynamics.

Technology-based explanations

The oldest explanation links firm size to technology and economies of scale. In industries where production technology involves heavy fixed costs – large machinery, continuous-process plants, or capital-intensive assembly lines – firms must operate at large scale to spread those costs and reach the minimum efficient size. Steel, cement, automobiles, and petrochemicals are classic examples where the technology itself pushes toward large firms.

In contrast, industries with low fixed costs and labour-intensive techniques – garments, food processing, handicrafts – can sustain many small, competitive firms. On this view, the size structure of an industry is largely dictated by its underlying production technology. Changes in technology, such as cheaper communication and digital tools, can also reshape firm boundaries, sometimes enabling flatter and more decentralised organisations.

Transaction cost explanations

A more subtle explanation asks why firms exist at all instead of all production happening through market contracts between individuals. The answer came from Ronald Coase in his 1937 paper “The Nature of the Firm,” for which he later won the Nobel Prize. Coase argued that the comparative costs of organising transactions through markets, rather than within firms, are the primary determinants of the size and scope of firms. When using the market is costly – searching for partners, negotiating, writing and enforcing contracts – it becomes cheaper to bring activities inside the firm.

This raises a puzzle famously posed by Frank Knight and Coase: if internalising transactions is efficient, why doesn’t one giant firm simply absorb the entire economy? The limits to firm size puzzle asks why a large firm can’t do everything a collection of smaller firms can do, and more. Oliver Williamson developed Coase’s insight into a formal, testable framework. He emphasised bounded rationality (people cannot foresee everything), opportunism (parties may behave self-interestedly), and asset specificity (investments tailored to a particular relationship). Williamson concluded that activities move inside the firm when transaction costs in the open market exceed internal costs. As firms grow, however, internal coordination costs rise, setting a natural limit on size. This balance between market and internal costs explains why firms settle at particular sizes rather than expanding indefinitely.

Political economy explanations

The third perspective argues that firm size is shaped not only by efficiency but by power, policy, and institutions. Government regulation, taxation, licensing, labour laws, and access to credit can all push the size structure in one direction or another. India’s reservation policy is a textbook example of politics determining firm size: small units were protected for political and social reasons even when this reduced efficiency. As one analysis of the reform noted, the policy was sustained for decades largely due to political considerations and the goal of protecting small entrepreneurs.

Labour regulations offer another illustration. When laws impose heavier compliance burdens on firms above a certain employee threshold, businesses may deliberately stay small to avoid them – producing a “missing middle” of mid-sized firms that is common in developing economies. Political economy explanations remind us that the firm size distribution is partly a product of the rules of the game, not just technology or transaction costs. Studies of India’s manufacturing have estimated that lifting size-based reservation restrictions could raise manufacturing output by nearly 7% by allowing resources to flow to more efficient, larger producers.

Bringing the theories together

No single theory fully explains firm size. Technology sets the broad constraints by defining minimum efficient scale. Transaction costs determine how much activity a firm internalises versus buys from the market. Political economy factors shape the environment in which firms decide whether to grow or stay small. In practice, all three forces operate at once, which is why the size structure of firms varies so much across industries and countries – and why understanding it is essential for anyone studying industrial growth and urban development.

What do you think? Should industrial policy actively protect small firms even at the cost of some efficiency, or should it focus on removing barriers so that firms can grow to their optimal size? And in an era of digital platforms and automation, do you expect the future to favour large integrated firms or networks of small, flexible enterprises?

References

PDF 📄

Analyzing the Size Structure of Firms in Industrial Growth

Table of Contents

The trajectory of firm size 🔗

From household enterprises to workshops 🔗

From factories to large-scale firms 🔗

Small versus large firms 🔗

The case for small firms 🔗

The case for large firms 🔗

The Indian reservation experiment 🔗

Theories of firm size 🔗

Technology-based explanations 🔗

Transaction cost explanations 🔗

Political economy explanations 🔗

Bringing the theories together 🔗