Table 15.9 shows the share of income going to each quintile of the income distribution for the United Kingdom in 1979 and 1991. Use this data to calculate what the points on a Lorenz curve would be, and sketch the Lorenz curve.

How did inequality in the United Kingdom shift over this time period? How can you see the patterns in the quintiles

in the Lorenz curves?

Share of Income	1979	1991
Top quintile	39.70%	42.90%
Fourth quintile	24.80%	22.70%
Middle quintile	17.00%	16.30%
Second quintile	11.50%	11.50%
Bottom quintile	7.00%	6.60%

The Lorenz curve is a way of showing income inequality in a country at a point in time. For illustrating the Lorenz curve,

the cumulative share of the population is taken on the horizontal axis and the cumulative percentage of total income received by each group is taken on the vertical axis. A 45-degree line is drawn that shows the perfect equality of income. Then the cumulative share of the total income for each group is plotted on the diagram. The Lorenz curve is obtained by joining the plotted points in the graph. In the below diagram the two Lorenz curves are shown for the two years. The Lorenz curve for the year 1991 has shifted up from the Lorenz curve for the year $1979$. Inequality has increased over this time period in the US.

The closer the Lorenz curve to the $45$-degree line, the less is the income inequality. The further the Lorenz curve to the $45$-degree line, the more is the income inequality.