Greater inequality can happen either because the wealthier are getting wealthier, or the poor are falling behind, or both. In America it has had more to do with the rich. The income of the wealthiest 20% of Americans rose 14% during the 1970s, when the income of the poorest fifth rose 9%. In the 1990s the income of the richest fifth rose 27% while that of the poorest fifth went up only 10%. That is a widening income spread, but not a drastic one. Robert Gordon, an economist at Northwestern University in Illinois, reckons that for the bottom 99% of the population, inequality has not risen since 1993.
The problems at the bottom are reasonably well understood: technology enables the automation of blue-collar trades; globalisation lets unskilled jobs move to poorer, cheaper countries; shrinking trade-union membership erodes workers’ bargaining power. But inequality is rising more sharply at the top, among what George Bush junior called the “haves and have-mores”. Here the causes are more mysterious.
The economists Emmanuel Saez and Thomas Piketty studied the incomes of the top 0.1% of earners in America, Britain and France in 1913-2008. America’s super-rich, they found, were earning about 8% of the country’s total income at the end of the period—the same share as during the Gilded Era of the 1920s and up from around 2% in the 1960s. A study by the Economic Policy Institute, a think-tank in Washington, DC, looked at the ratio of the average incomes of the rich and the “bottom” 90% of the population between 1980 and 2006. It found that the top 1% earned ten times more than the rest at the start of the period and 20 times as much at the end—ie, its “premium” doubled. But for the top 0.1% the gain rose from 20 times the earnings of the lower 90% to almost 80-fold.