Letter to the editor comments on Groparu-Cojocaru and Doray (2013)

Commun Stat Simul Comput. 2017;46(5):3833-3840. doi: 10.1080/03610918.2015.1024857. Epub 2015 Nov 21.

Abstract

Although estimating the five parameters of an unknown Generalized Normal Laplace (GNL) density by minimizing the distance between the empirical and true characteristic functions seems appealing, the approach cannot be advocated in practice. This conclusion is based on extensive numerical simulations in which a fast minimization procedure delivers deceiving estimators with values that are quite far away from the truth. These findings can be predicted by the very large values obtained for the true asymptotic variances of the estimators of the five parameters of the true GNL density.

Keywords: Generalized Normal Laplace; Pólya frequency function; characteristic function; least squares.