About the hyperbolic Lorenz curve

- Wang and Smyth (2015) propose a bi-parametric Lorenz curve.
- We demonstrate that it is a reparameterization of the hyperbolic Lorenz curve.
- We provide two different estimators for the parameters of the model.
- We obtain closed expressions for several inequality measures.

In a recent paper in this journal, Wang and Smyth (2015) propose a new bi-parametric functional form for the Lorenz curve and use it to derive new parametric forms. In this paper, we demonstrate that the new bi-parametric model is a reparameterization of the hyperbolic Lorenz curve proposed by Arnold (1986). We obtain new and important properties not previously considered.