IGCSE Geography / Economic activity and energy

Employment structure and the Clark Fisher model

Edexcel International GCSE Geography (4GE1), chapter 4: Economic activity and energy, specification point 4.1a. Free lesson.

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The Clark Fisher model shows how the share of workers in primary, secondary and tertiary work tends to change as a country develops. It helps you describe employment patterns and explain why they change, while recognising that countries do not all follow the same path.

What the Clark Fisher model shows

The model plots time against the share of workers in each sector. It has no dates because it represents a general pattern, not the history of one country. In the pre-industrial stage, most workers are in primary work. In the industrial stage, secondary work peaks. In the post-industrial stage, tertiary work becomes dominant. Primary work, such as farming, starts as the largest share and then falls. Secondary work, such as manufacturing, starts small, rises to a peak in the industrial stage, then falls. Tertiary work, or services, stays low at first, then rises to become…

How Ethiopia, China and the UK fit the stages

The 2025 figures show three countries at different stages. The shares are rounded, and tertiary includes quaternary. Match a country to the stage by looking at how the sector shares compare, not just at its development label. Ethiopia is developing, with a low HDI (Human Development Index). Its workers are 60% primary, 6% secondary and 34% tertiary, so it fits the pre-industrial stage. China is emerging, with a high HDI. Its shares are 22% primary, 32% secondary and 46% tertiary. Tertiary is its largest sector, but its secondary share is the highest of the three countries, so it fits…

Why employment structure changes

Changes in jobs are linked to changes in farming, industry and living standards. Each stage helps set up the next: fewer workers are needed on farms, factories grow, then rising incomes and education increase demand for services. At first, farms have few machines, so growing food needs many workers. This makes primary employment high. As farms mechanise, machines take over some work. Fewer farm workers are needed, so people leave the land and find jobs in factories. Secondary employment rises. Factory wages raise incomes, and the country can afford more schools. People spend more on…

A limitation of the model

The Clark Fisher model is a general rule drawn from the history of countries such as the UK. It does not describe every country's path. In Ethiopia, farming fell from about 77% of workers in 1991 to about 60% in 2025, while industry stayed at 6 to 7%. This suggests Ethiopia is moving from farming towards services without a large factory stage. Not every country follows the three stages in the same order.

How to identify a stage

Use the largest sector as evidence, then connect it to the stage where that sector is most important. For a full explanation, give a reason for the employment pattern rather than only naming a country's level of development. A made-up country has 25% of workers in primary, 45% in secondary and 30% in tertiary. Secondary is the largest sector at 45%, and secondary employment reaches its peak in the industrial stage. Therefore, the country is in the industrial stage.

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