Average-DICE: Stationary Distribution Correction by Regression

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Che, Fengdi, Chan, Bryan, Ma, Chen, Mahmood, A. Rupam
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866908483198124032
author Che, Fengdi
Chan, Bryan
Ma, Chen
Mahmood, A. Rupam
author_facet Che, Fengdi
Chan, Bryan
Ma, Chen
Mahmood, A. Rupam
contents Off-policy policy evaluation (OPE), an essential component of reinforcement learning, has long suffered from stationary state distribution mismatch, undermining both stability and accuracy of OPE estimates. While existing methods correct distribution shifts by estimating density ratios, they often rely on expensive optimization or backward Bellman-based updates and struggle to outperform simpler baselines. We introduce AVG-DICE, a computationally simple Monte Carlo estimator for the density ratio that averages discounted importance sampling ratios, providing an unbiased and consistent correction. AVG-DICE extends naturally to nonlinear function approximation using regression, which we roughly tune and test on OPE tasks based on Mujoco Gym environments and compare with state-of-the-art density-ratio estimators using their reported hyperparameters. In our experiments, AVG-DICE is at least as accurate as state-of-the-art estimators and sometimes offers orders-of-magnitude improvements. However, a sensitivity analysis shows that best-performing hyperparameters may vary substantially across different discount factors, so a re-tuning is suggested.
format Preprint
id arxiv_https___arxiv_org_abs_2503_02125
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Average-DICE: Stationary Distribution Correction by Regression
Che, Fengdi
Chan, Bryan
Ma, Chen
Mahmood, A. Rupam
Machine Learning
Off-policy policy evaluation (OPE), an essential component of reinforcement learning, has long suffered from stationary state distribution mismatch, undermining both stability and accuracy of OPE estimates. While existing methods correct distribution shifts by estimating density ratios, they often rely on expensive optimization or backward Bellman-based updates and struggle to outperform simpler baselines. We introduce AVG-DICE, a computationally simple Monte Carlo estimator for the density ratio that averages discounted importance sampling ratios, providing an unbiased and consistent correction. AVG-DICE extends naturally to nonlinear function approximation using regression, which we roughly tune and test on OPE tasks based on Mujoco Gym environments and compare with state-of-the-art density-ratio estimators using their reported hyperparameters. In our experiments, AVG-DICE is at least as accurate as state-of-the-art estimators and sometimes offers orders-of-magnitude improvements. However, a sensitivity analysis shows that best-performing hyperparameters may vary substantially across different discount factors, so a re-tuning is suggested.
title Average-DICE: Stationary Distribution Correction by Regression
topic Machine Learning
url https://arxiv.org/abs/2503.02125