The Pareto-Gamma Mixture

Abstract

In this paper we will review some established properties and derive some new properties of a Pareto distribution with fixed scale whose unknown shape parameter is Gamma distributed. Namely:

  • that Gamma is a conjugate prior to the Pareto distribution.
  • the formula for the posterior parameters of the Gamma given observed data.
  • a closed form for the CDF of the Pareto-Gamma mixture.
  • that the mean and all higher moments of the distribution are infinite.
  • a formula for the moments of the limited expected value of a random variable following this distribution.
  • the intractability of the closed form.
Issue
Spring
Year
2021
Keywords
Pareto distribution, Gamma distribution, Lomax distribution, conjugate prior, Bayesian statistics, large loss model
Publications
Casualty Actuarial Society E-Forum
Authors
Greg McNulty
Formerly on syllabus
Off