The US Census Bureau, for instance, uses income and publishes two measures of income inequality each year.
- The first shows the share of total annual income by income bracket groups. According to this measure, "the top 5% of households received 22.1% of “equivalence-adjusted” aggregate income last year — nearly as much as the bottom 60% of households (27.2%). (The “equivalence-adjusted” estimates adjust for different household sizes and compositions.)."
- The Census Bureau also reports the Gini index, "a summary statistic that measures the dispersion of incomes on a scale of zero (everyone has exactly the same income) to 1 (one person has all the income). The income Gini for the U.S. has been rising for decades: On an equivalence-adjusted basis, the Gini was 0.362 in 1967 and 0.463 last year." The US Gini is among the highest in the developed world.
Income Inequality in the US (http://www.teachingwithdata.org/resource/3182)
An Analysis of Earnings (http://www.teachingwithdata.org/resource/3159)
NYT Interactive: What Percent Are You? (http://www.teachingwithdata.org/resource/3913)
Recession Trends (http://www.teachingwithdata.org/resource/3067)