Library Economics 0455 3.5 Firms
O Level · Economics 0455

3.5 Firms

Revise 3.5 Firms for Economics 0455 (O Level) — revision notes and instant AI marking.

📖 Revision notes · preview

3.5 Firms

Understanding how firms classify, grow, and achieve efficiency

What You Need to Know

  • Firms can be classified by economic sector, ownership, and size
  • Small firms exist even in the presence of economies of scale, with distinct advantages and disadvantages
  • Firms grow internally (organic) or externally through mergers (inorganic)
  • Three types of inorganic growth: vertical, horizontal, and conglomerate integration
  • Economies of scale make production cheaper as firms get bigger; diseconomies of scale make it more expensive
  • External economies of scale benefit individual firms when their entire industry grows

1. Classification of Firms

Before we understand why firms behave differently or grow at different rates, we need a way to describe them. Economists classify firms using three main criteria: the economic sector they operate in, whether they are publicly or privately owned, and their relative size. This classification helps us compare firms and make predictions about their likely objectives and strategies.

The Three Economic Sectors

Every firm in the world operates in one of three economic sectors, depending on what it does with raw materials and labour:

Primary Sector
Firms involved in extracting or producing raw materials from the earth. Think: fishing, farming, mining, forestry, oil drilling. These firms work directly with nature. A good example is Tata Steel, which extracts iron ore and turns it into steel.
Secondary Sector
Firms that take raw materials and manufacture them into finished goods. They transform primary sector output. Car manufacturing, food processing, textiles, electronics assembly. A good example is Kellogg's, which takes raw grain and manufactures breakfast cereals.
Tertiary Sector
Firms that provide services rather than physical goods. Banking, education, tourism, retail, transport, healthcare. A good example is Expedia, which provides travel booking services.
Why Does This Matter for Exams?
Governments measure how developed an economy is by looking at the proportion of workers and GDP in each sector. Developed economies have more tertiary sector activity; developing economies still rely heavily on primary sector.

Two Key Metrics:

  • % of workers employed in each sector: In 2019, 84% of Singapore's workers were in the tertiary sector — a sign of a highly developed economy.
  • % of GDP generated by each sector: In 2021, 38% of Ethiopia's GDP came from primary sector activity — a sign of a developing economy still dependent on agriculture.
Which economic sector would a coffee plantation belong to, and why?

Public vs Private Sector

The second way to classify firms is by who owns and controls them:

Public Sector Firms
Owned and controlled by the government. Their primary goal is usually to provide a service to the public, not to maximise profit. They can operate at local level (e.g., Transport for London), regional level (e.g., Agricultural State Service in India), or national level (e.g., Caribbean Airlines).
🔓 Read the full 3.5 Firms note → You're seeing the preview · sign in to read it all
Also in the full note
  • 2. Small Firms
  • 3. The Growth of Firms
  • 4. Economies & Diseconomies of Scale
  • What to Memorise
  • Concepts Checklist
  • Common Exam Mistakes & Mark-Scheme Traps
  • The Relative Size of Firms
  • Six Reasons Why Small Firms Exist
What's inside
📖 Revision notes 🎯 Learn mode ✦ AI flashcards ✓ Instant AI marking 🧊 3D explorers 🧪 Experiments & simulations 📈 Progress tracking
📄 Practise 3.5 Firms with Economics 0455 past papers Every paper with its mark scheme — answer online, marked instantly. Open →

Read the full 3.5 Firms notes free

That's the preview — create a free account to read the rest, plus flashcards and practice questions with instant AI marking. No credit card.

Unlock the full notes free →

More Economics topics