Note: An updated version of this graph is here. Income
inequality in the United States has been rising since the 1970s.
What is the most effective way to succinctly convey this fact?
Here is my choice (a pdf version is available here): The chart
shows average inflation-adjusted incomes of the poorest 20%,
middle 60%, and top 1% of households since the 1970s. The
incomes include government transfers and subtract taxes. For the
bulk of American households, incomes have increased moderately
or minimally. For those at the top, by contrast, they have
soared. Why This Chart? Here are what I think should be the
principal considerations. Some are obvious, others perhaps not.
1. Tell the substantive story clearly. The graph does a good job
of conveying the two key aspects of the rise in income
inequality over the past generation. One is the dramatic
increase in incomes for households at the very top. In 1979
household income among those in the top 1% averaged $325,000 (in
2005 dollars). By 2005 that had increased to n