The variance-gamma ratio distribution

Let $X$ and $Y$ be independent variance-gamma random variables with zero location parameter; then the exact probability density function of the ratio $X/Y$ is derived. Some basic distributional properties are also derived, including identification of parameter regimes under which the density is boun...

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Bibliographic Details
Main Authors: Gaunt, Robert E., Li, Siqi
Format: Article
Language:English
Published: Académie des sciences 2023-10-01
Series:Comptes Rendus. Mathématique
Subjects:
Online Access:https://comptes-rendus.academie-sciences.fr/mathematique/articles/10.5802/crmath.495/
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Summary:Let $X$ and $Y$ be independent variance-gamma random variables with zero location parameter; then the exact probability density function of the ratio $X/Y$ is derived. Some basic distributional properties are also derived, including identification of parameter regimes under which the density is bounded, asymptotic approximations of tail probabilities, and fractional moments; in particular, we see that the mean is undefined. In the case that $X$ and $Y$ are independent symmetric variance-gamma random variables, an exact formula is also given for the cumulative distribution function of the ratio $X/Y$.
ISSN:1778-3569