Some New Results on the Beta Skew-Normal
Distribution
Valentina Mameli and Monica Musio
Abstract
In this paper we study the Beta skew-normal distribution introduced by Mameli
and Musio (2013). Some new properties of this distribution are derived including
formulae for moments in particular cases and bi-modality properties. Further-
more, we provide expansions for its distribution and density functions. Bounds
for the moments and the variance of the Beta skew-normal are derived. Some
of the results presented in this work can be extended to the entire family of the
Beta-generated distribution introduced by Jones (Test 13(1):1–43, 2004).
1 Introduction
The literature related to the skew-normal distribution (SN), introduced in [1], has
grown rapidly in recent years. Mameli and Musio [12] proposed a generalization
of the skew-normal called Beta skew-normal (BSN). This distribution arises quite
naturally if we consider the distribution function of the order statistics of the skew-
normal distribution and it can also be seen as a special case of the Beta-generated
family proposed by Jones [8]. In [12] the authors studied some properties of the
Beta skew-normal distribution. In particular, they derived the moment generating
function, recurrence relations for moments and two methods for simulating.
The main aim of this paper is to study some new properties of the Beta skew-
normal distribution. Particularly, inspired by Gupta and Nadarajah [6], we obtain
general expressions for the moments of the BSN. Expansions for its distribution and
density functions are also provided. Moreover, motivated by the well-known bounds
V. Mameli () • M. Musio
University of Cagliari, via Ospedale 72, Cagliari, Italy
e-mail: mameli.valentina@virgilio.it; mmusio@unica.it
© Springer International Publishing Switzerland 2016
G. Alleva, A. Giommi (eds.), Topics in Theoretical and Applied Statistics,
Studies in Theoretical and Applied Statistics,
DOI 10.1007/978-3-319-27274-0_3
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mameli.valentina@virgilio.it