Branches and how they link
The world economy is all the production and exchange of goods and services in the world. We split it into branches (industries). The 3D shows eight. None works alone. For example, a tractor needs steel (metallurgy), made in a factory (machine building) using energy, then reaches the farmer by transport that is paid for through finance and trade.
Energy and metallurgy
Energy means fuels (coal, oil, gas), electricity (from coal, gas, hydro, nuclear, wind, solar) and heat. Every other branch needs it, and it is a main reason for climate change, so the world is shifting to cleaner sources.
Metallurgy extracts metals from ore and makes alloys. Iron and steel are the heaviest users; aluminium, copper and others follow. Metallurgy needs much energy and is often near ore, coal or ports.
Machine building and chemicals
Machine building makes machines, tools, vehicles, ships, electronics and equipment. It needs steel, skilled workers and a market, and it supplies every other branch.
The chemical industry turns raw materials such as oil, gas, salts and minerals into fertilisers, plastics, medicines, paints and fibres. It needs energy, water and strict safety and pollution control.
Agriculture
Agriculture grows crops and raises animals for food and raw materials (cotton, rubber, timber). It still employs many people in poor countries but uses machines, fertilisers and irrigation more and more. It depends on climate, soil and water, and it links to food industries, transport and trade.
Transport, finance, trade and tourism
- Transport moves goods and people by road, rail, sea, air and pipeline. Sea carries most world cargo by weight.
- Finance (banks, insurance, markets) lends and moves money so that firms can build, buy and expand.
- Trade exchanges goods and services within and between countries. Tourism is the movement of visitors who spend money on stays, food and travel.
These three are services (tertiary sector). They connect producers and buyers worldwide.
Try it
Pick any product you own, such as a bicycle or a school bag. Write which of the eight branches touched it. Then in the 3D, pick each branch in free play and compare your list with the linked branches shown.
Key formulas and definitions
- Energy powers all branches
- Ore โ metal (metallurgy) โ machines (machine building)
- Trade balance = exports โ imports
- Transport time = distance รท speed
Worked examples
1. An ore contains 40% iron. How many kilograms of iron can 1 tonne (1000 kg) of this ore give, in the best case?
40% of 1000 kg = 0.40 ร 1000 = 400 kg of iron.
2. A factory uses 500 kWh of electricity per day. How much in 30 days?
500 ร 30 = 15,000 kWh.
3. A lorry must carry goods 600 km at an average speed of 60 km/h. How long does it take?
Time = 600 รท 60 = 10 hours.
4. A country exports goods worth 120 units and imports 90 units. What is the trade balance?
120 โ 90 = +30 units (a surplus).
Common mistakes
- Thinking each branch is independent. They rely on each other, so a problem in energy or transport spreads.
- Putting tourism in manufacturing. It is a service.
- Forgetting the cost of energy and pollution when counting metallurgy and chemicals as "good".
- Mixing "trade" (buying and selling) with "transport" (moving goods).