Piketty’s Inequality Story in Six Charts [newyorker.com]
Fifteen or twenty years ago, debates about inequality tended to be cast in terms of clever but complicated statistics, such as the Gini coefficient and the Theil entropy index, which attempted to reduce the entire income distribution to a single number. One thing that Piketty and his colleagues Emmanuel Saez and Anthony Atkinson have done is to popularize the use of simple charts that are easier to understand. In particular, they present pictures showing the shares of over-all income and wealth taken by various groups over time, including the top decile of the income distribution and the top percentile (respectively, the top ten per cent and those we call “the one per cent”).
The Piketty group didn’t invent this way of looking at things. Other economists, such as Ed Wolff, of New York University, and Jared Bernstein and Larry Mishel, the creators of the invaluable State of Working America series, have long used similar charts and tables in their publications. But partly by using new sources of data, such as individual tax records, and partly by expanding the research to other countries, Piketty and his colleagues have deployed their charts to reshape the entire inequality debate.