The three sectors: what is industrial structure?
The industrial structure of a region tells us how its economy is split between three groups of work. We usually measure the split in two ways: the share of workers and the share of money earned (output).
- Primary sector: uses nature directly. Farming, fishing, forestry, mining.
- Secondary sector: changes raw materials into goods. Factories, building, power plants.
- Tertiary sector: gives services. Trade, transport, banks, schools, health, tourism, software.
How the structure changes as a region grows
Most regions follow a pattern, though not exactly the same speed.
- Farming economy: most people farm. Incomes are low.
- Industrialising: machines make farming need fewer hands. Extra workers move to factories in towns. Incomes rise.
- Services rise: richer people spend on health, education, travel and entertainment. Factories also need transport, finance and design. Services grow and become the biggest sector.
Why does it happen? Better farm tools, new factories, higher incomes, cities, trade and new technology all push workers from one sector to the next. This shift is called structural change.
What is industrial upgrading?
Industrial upgrading means moving industry to a higher level. It is about quality, not only quantity.
- From labour-heavy work (many hands, low pay) to technology- and knowledge-heavy work (machines, design, research).
- From low value goods (basic cloth, raw steel) to high value goods (smart devices, medicines, special steel).
- From dirty and wasteful to clean and energy-saving.
- From only making things to also designing, branding and servicing them.
Why regions upgrade, and what helps
Why: wages rise so cheap-labour work moves elsewhere; land and water become costly; pollution must fall; other regions compete; old industries (like old coal or mill towns) may decline.
What helps: skilled workers and good schools, research, new machines and robots, better roads and internet, help from government, and a clean-energy supply.
Examples: Ruhr (Germany) moved from coal and steel to research and services. Shenzhen (China) moved from simple assembly to electronics design. Bengaluru (India) grew as a software and electronics hub. Challenges: some workers lose old jobs and need retraining.
Try it
In the 3D, use the slider through the four stages. Write down the farm, factory and service shares at each stage. At home: ask an older person what job their parents did, what job they did, and what jobs you see around you. Draw three bars for each generation.
Key formulas and definitions
- Primary + Secondary + Tertiary = 100% of workers (or output)
- Structural change: farming share falls, factory share rises, then service share rises
- Industrial upgrading = low value, dirty, labour-heavy industry becomes high value, clean, technology-heavy industry
- Value per worker = output / number of workers
Worked examples
1. A region has 100 workers: 60 farm, 25 work in factories. How many work in services, and what is the share of each sector?
Services = 100 - 60 - 25 = 15 workers. Shares: primary 60%, secondary 25%, tertiary 15%. This region is still mostly a farming economy.
2. In 30 years a town goes from 70% farming, 15% factory, 15% service to 20% farming, 35% factory, 45% service. Describe the change.
Farming fell by 50 points, factories rose by 20 points and services rose by 30 points. Workers moved from farms to factories and, even more, to services. Services now lead. This is structural change.
3. An old factory makes 100 shirts a day with 50 workers. After upgrading with machines it makes 240 shirts with 20 workers. Find output per worker before and after.
Before: 100 / 50 = 2 shirts per worker. After: 240 / 20 = 12 shirts per worker. Output per worker rose 6 times, but 30 jobs were lost, so retraining is needed.
4. Give three signs that a factory town is upgrading.
Any three: more skilled and technical workers, more machines and robots, more design and research, cleaner air and water, higher value products, more services around the factory such as software and logistics.
Common mistakes
- Thinking "upgrading" means more factories. It means better, cleaner, higher-value industry.
- Thinking services are not real work. Services employ the most people in rich economies.
- Believing farming disappears. It becomes smaller in share, but farm output can still grow with machines.
- Thinking every region follows the same path at the same speed. Resources, location and policy change the route.