Saved in:
Bibliographic Details
Main Authors: Kong, Jieming, Murthy, Karthyek
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2602.18756
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914342004326400
author Kong, Jieming
Murthy, Karthyek
author_facet Kong, Jieming
Murthy, Karthyek
contents We study the i.i.d. $k$-selection prophet inequality problem, where a decision-maker sequentially observes $n$ independent nonnegative rewards and may accept at most $k$ of them without knowledge of future realizations. The objective is to maximize the expected total reward relative to that of a prophet who observes all rewards in advance. This problem captures the performance limits achievable in online resource allocation and underlies posted-price mechanisms in online marketplaces. We characterize the optimal welfare achievable relative to the prophet in terms of $k$ and the extreme value index of the reward distribution, in the asymptotic regime where the number of offers $n$ grows large. This optimal performance ratio turns out to be at least $1-\frac{\log k}{8k}[1+ε]$ for any $ε> 0$ and sufficiently large $k$, improving upon the respective, tight $1 - \frac{1}{\sqrt{2πk}}$ guarantee of static-threshold algorithms. We additionally analyze the certainty-equivalent (CE) heuristic, a widely used online allocation algorithm known to yield optimal regret growth in $n$ when evaluated under the fluid scaling assumption. Even in the absence of the fluid scaling, the CE heuristics's performance improves with $k$ to eventually match the leading order terms of the optimal dynamic program's performance ratio. A finer analysis nevertheless reveals that regret can be divergent and large relative to the optimal dynamic program when $n/k \to \infty$. This highlights the sensitivity in viewing the CE heuristic's performance under the commonly adopted, though subjective, fluid scaling assumption.
format Preprint
id arxiv_https___arxiv_org_abs_2602_18756
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Multiunit I.I.D. Prophet Inequalities via Extreme Value Asymptotics
Kong, Jieming
Murthy, Karthyek
Optimization and Control
We study the i.i.d. $k$-selection prophet inequality problem, where a decision-maker sequentially observes $n$ independent nonnegative rewards and may accept at most $k$ of them without knowledge of future realizations. The objective is to maximize the expected total reward relative to that of a prophet who observes all rewards in advance. This problem captures the performance limits achievable in online resource allocation and underlies posted-price mechanisms in online marketplaces. We characterize the optimal welfare achievable relative to the prophet in terms of $k$ and the extreme value index of the reward distribution, in the asymptotic regime where the number of offers $n$ grows large. This optimal performance ratio turns out to be at least $1-\frac{\log k}{8k}[1+ε]$ for any $ε> 0$ and sufficiently large $k$, improving upon the respective, tight $1 - \frac{1}{\sqrt{2πk}}$ guarantee of static-threshold algorithms. We additionally analyze the certainty-equivalent (CE) heuristic, a widely used online allocation algorithm known to yield optimal regret growth in $n$ when evaluated under the fluid scaling assumption. Even in the absence of the fluid scaling, the CE heuristics's performance improves with $k$ to eventually match the leading order terms of the optimal dynamic program's performance ratio. A finer analysis nevertheless reveals that regret can be divergent and large relative to the optimal dynamic program when $n/k \to \infty$. This highlights the sensitivity in viewing the CE heuristic's performance under the commonly adopted, though subjective, fluid scaling assumption.
title Multiunit I.I.D. Prophet Inequalities via Extreme Value Asymptotics
topic Optimization and Control
url https://arxiv.org/abs/2602.18756