IGCSE Geography / Development and human welfare

Measuring inequality and corruption

Edexcel International GCSE Geography (4GE1), chapter 9: Development and human welfare, specification point 9.1c. Free lesson.

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Inequality measures how unevenly income is shared, while corruption measures how cleanly public power is used. These measures help describe human welfare and explain why corruption can slow development.

How to read a Gini coefficient

The Gini coefficient is one number showing how unequally income is shared in a country. It ranges from 0, when everyone has the same income, to 1, often printed as 100, when one person has all the income. So a higher Gini coefficient means greater inequality. Sweden has the lowest value in the comparison, 29.3, so it is the most equal of these countries. South Africa has the highest value, 54.1, so it is the most unequal of these countries. Nigeria's 33.9 is lower than the USA's 41.8. Nigeria is poorer, but its income is shared more evenly. Inequality and level of development are…

Compare the income share of the richest 10%

A second measure is the percentage of all income received by the richest 10% of people. It gives a direct picture of how much income goes to a small group. A higher share means income is more concentrated among the richest people. In Sweden, the richest tenth receive 22.3% of all income. Its Gini coefficient is 29.3, which suggests income is shared fairly evenly. In South Africa, the richest tenth receive 42.1% of all income. Its Gini coefficient is 54.1, showing that a small group holds much of the income. Both measures show greater inequality in South Africa than in Sweden.

Read the Corruption Perceptions Index

Corruption is the misuse of public power for private gain, such as paying a bribe to an official. The Corruption Perceptions Index (CPI) is a score built from data. Because corruption is hidden, the index is based on what experts and business people perceive. The CPI runs from 0, highly corrupt, to 100, very clean. A higher score is better, so a low score indicates more corruption. In 2025, the UK scored 70 and ranked 20th of 182 countries. Italy scored 53, South Africa 41, Kenya 30 and Nigeria 26. Nigeria's score of 26 is low, so corruption is seen as high. This scale runs in the…

How corruption holds development back

Corruption slows development through a chain of effects. When officials take bribes or steal public money, less of the budget reaches services. Bribes also add costs and make rules seem unreliable, so businesses and foreign investors may stay away. Less money for schools, clinics and roads means health and education suffer. Fewer investors can mean fewer jobs and less tax revenue. With less tax to spend on services, development slows further.

Compare two Gini coefficients

To compare inequality, state which country has the higher coefficient and explain what that means. Use both figures so the comparison is supported by evidence.

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