A data set that occurs frequently consists of the values or the percentage breakdown of several categories for two time periods. A common way of plotting these data is to use a pair of pie charts.

Editor’s Note: We’ve been looking at inequality quite a bit lately. In the piece ‘Land of the Free, Home of the Poor,’ we used a trio of pie charts broken down into five quintiles to illustrate ...

Pie charts are a way to show data. Pie charts show proportions of a whole. The circle of the pie chart represents the whole. That's a full 360 degrees. Each part, or slice, represents part of the ...

Software packages for charting data often offer menus; i.e., lists of charts that are available. Excel offers a menu; Tableau has Show Me! Elementary statistics and graphing books offer recipes; i.e., ...

Editor's Note: We've been looking at inequality quite a bit lately. In the piece 'Land of the Free, Home of the Poor,' we used a trio of pie charts broken down into five quintiles to illustrate ...