Regret Minimization and Statistical Inference in Online Decision Making with High-dimensional Covariates

Fuente: arXiv
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Auteurs principaux: Duan, Congyuan, Ma, Wanteng, Jiang, Jiashuo, Xia, Dong
Format: Preprint
Publié: 2024
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author Duan, Congyuan
Ma, Wanteng
Jiang, Jiashuo
Xia, Dong
author_facet Duan, Congyuan
Ma, Wanteng
Jiang, Jiashuo
Xia, Dong
contents This paper investigates regret minimization, statistical inference, and their interplay in high-dimensional online decision-making based on the sparse linear context bandit model. We integrate the $\varepsilon$-greedy bandit algorithm for decision-making with a hard thresholding algorithm for estimating sparse bandit parameters and introduce an inference framework based on a debiasing method using inverse propensity weighting. Under a margin condition, our method achieves either $O(T^{1/2})$ regret or classical $O(T^{1/2})$-consistent inference, indicating an unavoidable trade-off between exploration and exploitation. If a diverse covariate condition holds, we demonstrate that a pure-greedy bandit algorithm, i.e., exploration-free, combined with a debiased estimator based on average weighting can simultaneously achieve optimal $O(\log T)$ regret and $O(T^{1/2})$-consistent inference. We also show that a simple sample mean estimator can provide valid inference for the optimal policy's value. Numerical simulations and experiments on Warfarin dosing data validate the effectiveness of our methods.
format Preprint
id arxiv_https___arxiv_org_abs_2411_06329
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Regret Minimization and Statistical Inference in Online Decision Making with High-dimensional Covariates
Duan, Congyuan
Ma, Wanteng
Jiang, Jiashuo
Xia, Dong
Machine Learning
This paper investigates regret minimization, statistical inference, and their interplay in high-dimensional online decision-making based on the sparse linear context bandit model. We integrate the $\varepsilon$-greedy bandit algorithm for decision-making with a hard thresholding algorithm for estimating sparse bandit parameters and introduce an inference framework based on a debiasing method using inverse propensity weighting. Under a margin condition, our method achieves either $O(T^{1/2})$ regret or classical $O(T^{1/2})$-consistent inference, indicating an unavoidable trade-off between exploration and exploitation. If a diverse covariate condition holds, we demonstrate that a pure-greedy bandit algorithm, i.e., exploration-free, combined with a debiased estimator based on average weighting can simultaneously achieve optimal $O(\log T)$ regret and $O(T^{1/2})$-consistent inference. We also show that a simple sample mean estimator can provide valid inference for the optimal policy's value. Numerical simulations and experiments on Warfarin dosing data validate the effectiveness of our methods.
title Regret Minimization and Statistical Inference in Online Decision Making with High-dimensional Covariates
topic Machine Learning
url https://arxiv.org/abs/2411.06329