On Egghe's version of continuous concentration theory

In a recent article, Egghe (2005) discussed what he terms Lorenz concentration theory, covering the Lorenz curve and concentration measures such as the coefficient of variation and the Theil and Gini coefficients. In this note, we point out that neither the curve construction nor the concentration measures conform to the standard statistical/econometric definitions. We here give the standard formulations and apply them to the (truncated) Pareto distributions that are the subject of Egghe's (2005) article. We also interpret Egghe's usage.