Asymptotics of generalized Pólya urns with non-linear feedback

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Gottfried, Thomas, Grosskinsky, Stefan
Natura: Preprint
Pubblicazione: 2023
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866909447814643712
author Gottfried, Thomas
Grosskinsky, Stefan
author_facet Gottfried, Thomas
Grosskinsky, Stefan
contents Generalized Pólya urns with non-linear feedback are an established probabilistic model to describe the dynamics of growth processes with reinforcement, a generic example being competition of agents in evolving markets. It is well known which conditions on the feedback mechanism lead to monopoly where a single agent achieves full market share, and various further results for particular feedback mechanisms have been derived from different perspectives. In this paper we provide a comprehensive account of the possible asymptotic behaviour for a large general class of feedback, and describe in detail how monopolies emerge in a transition from sub-linear to super-linear feedback via hierarchical states close to linearity. We further distinguish super- and sub-exponential feedback, which show conceptually interesting differences to understand the monopoly case, and study robustness of the asymptotics with respect to initial conditions, heterogeneities and small changes of the feedback mechanisms. Finally, we derive a scaling limit for the full time evolution of market shares in the limit of diverging initial market size, including the description of typical fluctuations and extending previous results in the context of stochastic approximation.
format Preprint
id arxiv_https___arxiv_org_abs_2303_01210
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Asymptotics of generalized Pólya urns with non-linear feedback
Gottfried, Thomas
Grosskinsky, Stefan
Probability
60J05, 60F17, 62L20, 91B62
Generalized Pólya urns with non-linear feedback are an established probabilistic model to describe the dynamics of growth processes with reinforcement, a generic example being competition of agents in evolving markets. It is well known which conditions on the feedback mechanism lead to monopoly where a single agent achieves full market share, and various further results for particular feedback mechanisms have been derived from different perspectives. In this paper we provide a comprehensive account of the possible asymptotic behaviour for a large general class of feedback, and describe in detail how monopolies emerge in a transition from sub-linear to super-linear feedback via hierarchical states close to linearity. We further distinguish super- and sub-exponential feedback, which show conceptually interesting differences to understand the monopoly case, and study robustness of the asymptotics with respect to initial conditions, heterogeneities and small changes of the feedback mechanisms. Finally, we derive a scaling limit for the full time evolution of market shares in the limit of diverging initial market size, including the description of typical fluctuations and extending previous results in the context of stochastic approximation.
title Asymptotics of generalized Pólya urns with non-linear feedback
topic Probability
60J05, 60F17, 62L20, 91B62
url https://arxiv.org/abs/2303.01210