Measuring Income Inequality

Read this article about the Lorenz Curve, which seeks to measure income inequality. Make sure to answer the "Try It" quiz questions, and check your answers.

6. Measuring Income Inequality

The U.S. economy has a relatively high degree of income inequality by global standards. As Table 3 shows, based on a variety of national surveys done for a selection of years in the last five years of the 2000s (with the exception of Germany, and adjusted to make the measures more comparable), the U.S. economy has greater inequality than Germany (along with most Western European countries). The region of the world with the highest level of income inequality is Latin America, illustrated in the numbers for Brazil and Mexico. The level of inequality in the United States is lower than in some of the low-income countries of the world, like China and Nigeria, or some middle-income countries like the Russian Federation. However, not all poor countries have highly unequal income distributions; India provides a counterexample.

Table 3. Income Distribution in Select Countries

Country

Survey Year

First Quintile

Second Quintile

Third Quintile

Fourth Quintile

Fifth Quintile

United States

2011

3.2%

8.4%

14.3%

23.0%

51.1%

Germany

2000

8.5%

13.7%

17.8%

23.1%

36.9%

Brazil

2009

2.9%

7.1%

12.4%

19.0%

58.6%

Mexico

2010

4.9%

8.8%

13.3%

20.2%

52.8%

China

2009

4.7%

9.7%

15.3%

23.2%

47.1%

India

2010

8.5%

12.1%

15.7%

20.8%

42.8%

Russia

2009

6.1%

10.4%

14.8%

21.3%

47.1%

Nigeria

2010

4.4%

8.3%

13.0%

20.3%

54.0%