which we show in the first and third columns of numbers in Table 15.6, into cumulative income, which we

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15.4 • Income Inequality: Measurement and Causes 373

show in the second and fourth columns of numbers. For example, the bottom 40% of the cumulative income

distribution will be the sum of the first and second quintiles; the bottom 60% of the cumulative income

distribution will be the sum of the first, second, and third quintiles, and so on. The final entry in the cumulative

income column needs to be 100%, because by definition, 100% of the population receives 100% of the income.

Income

Share of Income

Cumulative Share of

Share of Income

Cumulative Share of

Category

in 1980 (%)

Income in 1980 (%)

in 2020 (%)

Income in 2020 (%)

First

quintile

Second

quintile

Third

quintile

Fourth

quintile

Fifth

quintile

4.2

10.2

16.8

24.7

44.1

4.2

14.4

31.2

55.9

100.0

3.0

8.1

14.0

22.6

52.2

3.0

11.1

25.1

47.7

100.0
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