This graphic works as well as it does in part because it evokes the too-delicate feel of a champagne glass in hand. All that wealth resting on so little. The shape does what a data table alone cannot – it subtly suggests that the wealthy are resting on the poor and that the balance is quite precarious.
Conley, D. (2008) You may ask yourself: An introduction to thinking like a sociologist. New York: W.W. Norton and Company. p.392.
Chandler, David. L curve [another graphic depicting wealth distribution by a mathematician/educator - it's interactive.]
I found a much earlier 1992 version of the champagne glass distribution of wealth graphic and wanted to give credit where credit is due. It came from the UNDP 1992 “Human Development Report” and was republished in chapter 7 of When Corporations Rule the World by David Korten.