Abstract: Discusses how best to display distributions of income and wealth so that comparisons can be made between different periods or countries. The various different kinds of distribution curve that have been used are described and their disadvantages noted. The account starts with the frequency distribution curve, which is shown to have several drawbacks, and goes on to the Gini coefficient, which is based on the Lorenz curve, the indices proposed by Henri Theil and A. B. Atkinson, and the Pen parade (or Pen profile). The second section of the chapter provides a definition of income and discusses the choice of unit. The last section is a statistical appendix, and gives further details of the methods of distribution display discussed at the beginning of the chapter, and introduces some other indices––the Phelps Brown–Hopkins index, the Schumpeter–Gilboy index, and the Rousseau index.

Keywords: Atkinson index, display methods, frequency distribution curve, Gini coefficient, income, income distribution, Lorenz curve, Pen parade, Pen profile, Phelps Brown–Hopkins index, Rousseau index, Schumpeter–Gilboy index, statistics, Theil index, units, wealth distribution,