A parametric approach to the estimation of convex risk functionals based on Wasserstein distance

Fuente: arXiv
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Main Authors: Nendel, Max, Sgarabottolo, Alessandro
Format: Preprint
Published: 2022
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author Nendel, Max
Sgarabottolo, Alessandro
author_facet Nendel, Max
Sgarabottolo, Alessandro
contents In this paper, we explore a static setting for the assessment of risk in the context of mathematical finance and actuarial science that takes into account model uncertainty in the distribution of a possibly infinite-dimensional risk factor. We allow for perturbations around a baseline model, measured via Wasserstein distance, and we investigate to which extent this form of probabilistic imprecision can be parametrized. The aim is to come up with a convex risk functional that incorporates a sefety margin with respect to nonparametric uncertainty and still can be approximated through parametrized models. The particular form of the parametrization allows us to develop a numerical method, based on neural networks, which gives both the value of the risk functional and the optimal perturbation of the reference measure. Moreover, we study the problem under additional constraints on the perturbations, namely, a mean and a martingale constraint. We show that, in both cases, under suitable conditions on the loss function, it is still possible to estimate the risk functional by passing to a parametric family of perturbed models, which again allows for a numerical approximation via neural networks.
format Preprint
id arxiv_https___arxiv_org_abs_2210_14340
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle A parametric approach to the estimation of convex risk functionals based on Wasserstein distance
Nendel, Max
Sgarabottolo, Alessandro
Risk Management
Probability
Mathematical Finance
Primary 62G05, 90C31, Secondary 41A60, 68T07, 91G70
In this paper, we explore a static setting for the assessment of risk in the context of mathematical finance and actuarial science that takes into account model uncertainty in the distribution of a possibly infinite-dimensional risk factor. We allow for perturbations around a baseline model, measured via Wasserstein distance, and we investigate to which extent this form of probabilistic imprecision can be parametrized. The aim is to come up with a convex risk functional that incorporates a sefety margin with respect to nonparametric uncertainty and still can be approximated through parametrized models. The particular form of the parametrization allows us to develop a numerical method, based on neural networks, which gives both the value of the risk functional and the optimal perturbation of the reference measure. Moreover, we study the problem under additional constraints on the perturbations, namely, a mean and a martingale constraint. We show that, in both cases, under suitable conditions on the loss function, it is still possible to estimate the risk functional by passing to a parametric family of perturbed models, which again allows for a numerical approximation via neural networks.
title A parametric approach to the estimation of convex risk functionals based on Wasserstein distance
topic Risk Management
Probability
Mathematical Finance
Primary 62G05, 90C31, Secondary 41A60, 68T07, 91G70
url https://arxiv.org/abs/2210.14340