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Edgeworth expansions for multivariate random sums

Javed, Farrukh LU ; Loperfido, Nicola and Mazur, Stepan LU (2024) In Econometrics and Statistics 31. p.66-80
Abstract
The sum of a random number of independent and identically distributed random vectors has a distribution which is not analytically tractable, in the general case. The problem has been addressed by means of asymptotic approximations embedding the number of summands in a stochastically increasing sequence. Another approach relies on fitting flexible and tractable parametric, multivariate distributions, as for example finite mixtures. Both approaches are investigated within the framework of Edgeworth expansions. A general formula for the fourth-order cumulants of the random sum of independent and identically distributed random vectors is derived and it is shown that the above mentioned asymptotic approach does not necessarily lead to valid... (More)
The sum of a random number of independent and identically distributed random vectors has a distribution which is not analytically tractable, in the general case. The problem has been addressed by means of asymptotic approximations embedding the number of summands in a stochastically increasing sequence. Another approach relies on fitting flexible and tractable parametric, multivariate distributions, as for example finite mixtures. Both approaches are investigated within the framework of Edgeworth expansions. A general formula for the fourth-order cumulants of the random sum of independent and identically distributed random vectors is derived and it is shown that the above mentioned asymptotic approach does not necessarily lead to valid asymptotic normal approximations. The problem is addressed by means of Edgeworth expansions. Both theoretical and empirical results suggest that mixtures of two multivariate normal distributions with proportional covariance matrices satisfactorily fit data generated from random sums where the counting random variable and the random summands are Poisson and multivariate skew-normal, respectively. (Less)
Abstract (Swedish)
The sum of a random number of independent and identically distributed random vectors has a distribution which is not analytically tractable, in the general case. The problem has been addressed by means of asymptotic approximations embedding the number of summands in a stochastically increasing sequence. Another approach relies on fitting flexible and tractable parametric, multivariate distributions, as for example finite mixtures. Both approaches are investigated within the framework of Edgeworth expansions. A general formula for the fourth-order cumulants of the random sum of independent and identically distributed random vectors is derived and it is shown that the above mentioned asymptotic approach does not necessarily lead to valid... (More)
The sum of a random number of independent and identically distributed random vectors has a distribution which is not analytically tractable, in the general case. The problem has been addressed by means of asymptotic approximations embedding the number of summands in a stochastically increasing sequence. Another approach relies on fitting flexible and tractable parametric, multivariate distributions, as for example finite mixtures. Both approaches are investigated within the framework of Edgeworth expansions. A general formula for the fourth-order cumulants of the random sum of independent and identically distributed random vectors is derived and it is shown that the above mentioned asymptotic approach does not necessarily lead to valid asymptotic normal approximations. The problem is addressed by means of Edgeworth expansions. Both theoretical and empirical results suggest that mixtures of two multivariate normal distributions with proportional covariance matrices satisfactorily fit data generated from random sums where the counting random variable and the random summands are Poisson and multivariate skew-normal, respectively. (Less)
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author
; and
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Edgeworth expansion, Fourth cumulant, Random sum, Skew-normal
in
Econometrics and Statistics
volume
31
pages
66 - 80
publisher
Elsevier
external identifiers
  • scopus:85107137392
ISSN
2452-3062
DOI
10.1016/j.ecosta.2021.04.005
language
English
LU publication?
no
id
73b3a088-e895-4210-bc41-6715123686ba
date added to LUP
2026-04-20 13:31:04
date last changed
2026-04-21 04:00:57
@article{73b3a088-e895-4210-bc41-6715123686ba,
  abstract     = {{The sum of a random number of independent and identically distributed random vectors has a distribution which is not analytically tractable, in the general case. The problem has been addressed by means of asymptotic approximations embedding the number of summands in a stochastically increasing sequence. Another approach relies on fitting flexible and tractable parametric, multivariate distributions, as for example finite mixtures. Both approaches are investigated within the framework of Edgeworth expansions. A general formula for the fourth-order cumulants of the random sum of independent and identically distributed random vectors is derived and it is shown that the above mentioned asymptotic approach does not necessarily lead to valid asymptotic normal approximations. The problem is addressed by means of Edgeworth expansions. Both theoretical and empirical results suggest that mixtures of two multivariate normal distributions with proportional covariance matrices satisfactorily fit data generated from random sums where the counting random variable and the random summands are Poisson and multivariate skew-normal, respectively.}},
  author       = {{Javed, Farrukh and Loperfido, Nicola and Mazur, Stepan}},
  issn         = {{2452-3062}},
  keywords     = {{Edgeworth expansion; Fourth cumulant; Random sum; Skew-normal}},
  language     = {{eng}},
  pages        = {{66--80}},
  publisher    = {{Elsevier}},
  series       = {{Econometrics and Statistics}},
  title        = {{Edgeworth expansions for multivariate random sums}},
  url          = {{http://dx.doi.org/10.1016/j.ecosta.2021.04.005}},
  doi          = {{10.1016/j.ecosta.2021.04.005}},
  volume       = {{31}},
  year         = {{2024}},
}