14.4 Income inequality: measurement and causes  (Page 13/20)

Just from glancing at the quintile information, it is fairly obvious that income inequality increased in the United Kingdom over this time: The top quintile is getting a lot more, and the lowest quintile is getting a bit less. Converting this information into a Lorenz curve, however, is a little trickier, because the Lorenz curve graphs the cumulative distribution, not the amount received by individual quintiles. Thus, as explained in the text, you have to add up the individual quintile data to convert the data to this form. The following table shows the actual calculations for the share of income in 1979 versus 1991. The figure following the table shows the perfect equality line and the Lorenz curves for 1979 and 1991. As shown, the income distribution in 1979 was closer to the perfect equality line than the income distribution in 1991—that is, the United Kingdom income distribution became more unequal over time. Share of income received 1979 1991 Bottom 20% 7.0% 6.6% Bottom 40% 18.5% 18.1% Bottom 60% 35.5% 34.4% Bottom 80% 60.3% 57.1% All 100% 100.0% 100.0%