Long-Term Fairness in Reinforcement Learning with Bisimulation Metrics

Sahand Rezaei-Shoshtari, Hanna Yurchyk, Scott Fujimoto, Doina Precup, David Meger

Keywords: fairness, reinforcement learning, bisimulation

TL;DR: We use bisimulation metrics to optimize the reward function and observation dynamics in an MDP in order to achieve long-term fairness.

Abstract: Ensuring long-term fairness is crucial when developing automated decision making systems, specifically in dynamic and sequential environments. By maximizing their reward without consideration of fairness, AI agents can introduce disparities in their treatment of groups or individuals. In this paper, we establish the connection between bisimulation metrics and group fairness in reinforcement learning. We propose a novel approach that leverages bisimulation metrics to learn reward functions and observation dynamics, ensuring that learners treat groups fairly while reflecting the original problem. We demonstrate the effectiveness of our method in addressing disparities in sequential decision making problems through empirical evaluation on a standard fairness benchmark consisting of lending and college admission scenarios.

Primary Area: alignment, fairness, safety, privacy, and societal considerations

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Submission Number: 5067