The Central Role of the Loss Function in Reinforcement Learning
Not on the map. Why?
Abstract (arXiv)
This paper illustrates the central role of loss functions in data-driven decision making, providing a comprehensive survey on their influence in cost-sensitive classification (CSC) and reinforcement learning (RL). We demonstrate how different regression loss functions affect the sample efficiency and adaptivity of value-based decision making algorithms. Across multiple settings, we prove that algorithms using the binary cross-entropy loss achieve first-order bounds scaling with the optimal policy's cost and are much more efficient than the commonly used squared loss. Moreover, we prove that distributional algorithms using the maximum likelihood loss achieve second-order bounds scaling with the policy variance and are even sharper than first-order bounds. This in particular proves the benefits of distributional RL. We hope that this paper serves as a guide analyzing decision making algorithms with varying loss functions, and can inspire the reader to seek out better loss functions to improve any decision making algorithm.
Key facts. Cited by 8 papers in the map (data through 7 Oct 2026). Builds on 49 of its 77 references that are in the map. First posted on arXiv 19 Sep 2024.
Builds on
49 of 77 references.
References · 49
- 2022Training language models to follow instructions with human feedbackcited by 15,712
- 2020Conservative Q-Learning for Offline Reinforcement Learningcited by 1,777
- 2017A Distributional Perspective on Reinforcement Learningcited by 743
- 2018Implicit Quantile Networks for Distributional Reinforcement Learningcited by 362
- 2019Information-Theoretic Considerations in Batch Reinforcement Learningcited by 285
- 2021Bridging Offline Reinforcement Learning and Imitation Learning: A Tale of Pessimismcited by 275
- 2021Bellman-consistent Pessimism for Offline Reinforcement Learningcited by 267
- 2020FLAMBE: Structural Complexity and Representation Learning of Low Rank MDPscited by 232
- 2021Bellman Eluder Dimension: New Rich Classes of RL Problems, and Sample-Efficient Algorithmscited by 222
- 2021The Statistical Complexity of Interactive Decision Makingcited by 208
- 2021Pessimistic Model-based Offline Reinforcement Learning under Partial Coveragecited by 160
- 2022Hybrid RL: Using Both Offline and Online Data Can Make RL Efficientcited by 158
37 more
- 2024Nemotron-4 340B Technical Reportcited by 143
- 2024Stop Regressing: Training Value Functions via Classification for Scalable Deep RLcited by 136
- 2019Kinematic State Abstraction and Provably Efficient Rich-Observation Reinforcement Learningcited by 114
- 2022Adversarially Trained Actor Critic for Offline Reinforcement Learningcited by 111
- 2022When Is Partially Observable Reinforcement Learning Not Scary?cited by 100
- 2018Practical Contextual Bandits with Regression Oraclescited by 92
- 2021Model-free Representation Learning and Exploration in Low-rank MDPscited by 82
- 2022The Role of Coverage in Online Reinforcement Learningcited by 82
- 2021Conservative Offline Distributional Reinforcement Learningcited by 78
- 2024Is Behavior Cloning All You Need? Understanding Horizon in Imitation Learningcited by 74
- 2018On Oracle-Efficient PAC RL with Rich Observationscited by 71
- 2020Exponential Lower Bounds for Planning in MDPs With Linearly-Realizable Optimal Action-Value Functionscited by 71
- 2021Offline Reinforcement Learning: Fundamental Barriers for Value Function Approximationcited by 69
- 2018Improving Regression Performance with Distributional Lossescited by 66
- 2024REBEL: Reinforcement Learning via Regressing Relative Rewardscited by 66
- 2021Efficient First-Order Contextual Bandits: Prediction, Allocation, and Triangular Discriminationcited by 53
- 2020Fast Rates for Contextual Linear Optimizationcited by 43
- 2024Conditional Language Policy: A General Framework for Steerable Multi-Objective Finetuningcited by 42
- 2020Logistic Q-Learningcited by 34
- 2022Doubly Robust Distributionally Robust Off-Policy Evaluation and Learningcited by 34
- 2018Learning to Optimize Join Queries With Deep Reinforcement Learningcited by 32
- 2022On the Complexity of Adversarial Decision Makingcited by 32
- 2023Near-Minimax-Optimal Risk-Sensitive Reinforcement Learning with CVaRcited by 32
- 2022Guarantees for Epsilon-Greedy Reinforcement Learning with Function Approximationcited by 29
- 2023The Benefits of Being Distributional: Small-Loss Bounds for Reinforcement Learningcited by 27
- 2024More Benefits of Being Distributional: Second-Order Bounds for Reinforcement Learningcited by 23
- 2023Distributional Offline Policy Evaluation with Predictive Error Guaranteescited by 19
- 2017Small-loss bounds for online learning with partial informationcited by 18
- 2022Learning Bellman Complete Representations for Offline Policy Evaluationcited by 17
- 2023On the Convergence and Sample Complexity Analysis of Deep Q-Networks with ε-Greedy Explorationcited by 17
- 2023Efficient Model-Free Exploration in Low-Rank MDPscited by 16
- 2024A Reductions Approach to Risk-Sensitive Reinforcement Learning with Optimized Certainty Equivalentscited by 15
- 2024The Power of Resets in Online Reinforcement Learningcited by 14
- 2021Provably Correct Optimization and Exploration with Non-linear Policiescited by 13
- 2024Model-based RL as a Minimalist Approach to Horizon-Free and Second-Order Boundscited by 11
- 2024Switching the Loss Reduces the Cost in Batch (Offline) Reinforcement Learningcited by 8
- 2024Efficient and Sharp Off-Policy Evaluation in Robust Markov Decision Processescited by 3
Built on by
Citing papers per year: 2024: 2; 2025: 5; 2026: 1.
8 papers.
- 2025Bigger, Regularized, Categorical: High-Capacity Value Functions are Efficient Multi-Task Learnerscited by 23
- 2024Diffusing States and Matching Scores: A New Framework for Imitation Learningcited by 16
- 2025Qsharp: Provably Optimal Distributional RL for LLM Post-Trainingcited by 14
- 2024Second Order Bounds for Contextual Bandits with Function Approximationcited by 9
- 2025Catoni Contextual Bandits are Robust to Heavy-tailed Rewardscited by 3
- 2025SquarechiPO: Differentially Private and Robust chi2-Preference Optimization in Offline Direct Alignmentcited by 3
- 2025Efficient Controllable Diffusion via Optimal Classifier Guidancecited by 2
- 2026Eluder dimension: localise it!cited by 2
- 2026Eluder dimension: localise it!14 Jan 2026
- 2025Bigger, Regularized, Categorical: High-Capacity Value Functions are Efficient Multi-Task Learners29 May 2025
- 2025Efficient Controllable Diffusion via Optimal Classifier Guidance27 May 2025
- 2025SquarechiPO: Differentially Private and Robust chi2-Preference Optimization in Offline Direct Alignment27 May 2025
- 2025Qsharp: Provably Optimal Distributional RL for LLM Post-Training27 Feb 2025
- 2025Catoni Contextual Bandits are Robust to Heavy-tailed Rewards4 Feb 2025
- 2024Diffusing States and Matching Scores: A New Framework for Imitation Learning17 Oct 2024
- 2024Second Order Bounds for Contextual Bandits with Function Approximation24 Sep 2024