# Risk-Sensitive Reinforcement Learning: Near-Optimal Risk-Sample Tradeoff in Regret

arXiv: https://arxiv.org/abs/2006.13827 · HTML: https://mlsanity.com/paper/2006.13827/

## Key facts

- Cited by 58 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 22 Jun 2020.

## Built on by (most cited first, 30 of 58)

- [Recent Advances in Reinforcement Learning in Finance](https://mlsanity.com/paper/2112.04553/) (2021)
- [Reinforcement Learning with Human Feedback: Learning Dynamic Choices via Pessimism](https://mlsanity.com/paper/2305.18438/) (2023)
- [Exponential Bellman Equation and Improved Regret Bounds for Risk-Sensitive Reinforcement Learning](https://mlsanity.com/paper/2111.03947/) (2021)
- [Near-Minimax-Optimal Risk-Sensitive Reinforcement Learning with CVaR](https://mlsanity.com/paper/2302.03201/) (2023)
- [Disentangling Epistemic and Aleatoric Uncertainty in Reinforcement Learning](https://mlsanity.com/paper/2206.01558/) (2022)
- [Learning Stochastic Shortest Path with Linear Function Approximation](https://mlsanity.com/paper/2110.12727/) (2021)
- [Provably Efficient Risk-Sensitive Reinforcement Learning: Iterated CVaR and Worst Path](https://mlsanity.com/paper/2206.02678/) (2022)
- [On the Convergence and Optimality of Policy Gradient for Markov Coherent Risk](https://mlsanity.com/paper/2103.02827/) (2021)
- [RiskQ: Risk-sensitive Multi-Agent Reinforcement Learning Value Factorization](https://mlsanity.com/paper/2311.01753/) (2023)
- [Robust Risk-Aware Reinforcement Learning](https://mlsanity.com/paper/2108.10403/) (2021)
- [Soft Robust MDPs and Risk-Sensitive MDPs: Equivalence, Policy Gradient, and Sample Complexity](https://mlsanity.com/paper/2306.11626/) (2023)
- [Learn to Match with No Regret: Reinforcement Learning in Markov Matching Markets](https://mlsanity.com/paper/2203.03684/) (2022)
- [Bridging Distributional and Risk-sensitive Reinforcement Learning with Provable Regret Bounds](https://mlsanity.com/paper/2210.14051/) (2022)
- [A Reductions Approach to Risk-Sensitive Reinforcement Learning with Optimized Certainty Equivalents](https://mlsanity.com/paper/2403.06323/) (2024)
- [Derivative-Free Policy Optimization for Linear Risk-Sensitive and Robust Control Design: Implicit Regularization and Sample Complexity](https://mlsanity.com/paper/2101.01041/) (2021)
- [Risk-Sensitive Reinforcement Learning with Exponential Criteria](https://mlsanity.com/paper/2212.09010/) (2022)
- [Regret Bounds for Markov Decision Processes with Recursive Optimized Certainty Equivalents](https://mlsanity.com/paper/2301.12601/) (2023)
- [Convergence and Alignment of Gradient Descent with Random Backpropagation Weights](https://mlsanity.com/paper/2106.06044/) (2021)
- [Risk-Aware Transfer in Reinforcement Learning using Successor Features](https://mlsanity.com/paper/2105.14127/) (2021)
- [Continuous-time Risk-sensitive Reinforcement Learning via Quadratic Variation Penalty](https://mlsanity.com/paper/2404.12598/) (2024)
- [RA-PbRL: Provably Efficient Risk-Aware Preference-Based Reinforcement Learning](https://mlsanity.com/paper/2410.23569/) (2024)
- [Regret Bounds for Risk-sensitive Reinforcement Learning with Lipschitz Dynamic Risk Measures](https://mlsanity.com/paper/2306.02399/) (2023)
- [Complex behavior from intrinsic motivation to occupy action-state path space](https://mlsanity.com/paper/2205.10316/) (2022)
- [Risk-sensitive Markov Decision Process and Learning under General Utility Functions](https://mlsanity.com/paper/2311.13589/) (2023)
- [Risk-Sensitive Soft Actor-Critic for Robust Deep Reinforcement Learning under Distribution Shifts](https://mlsanity.com/paper/2402.09992/) (2024)
- [Towards Efficient Risk-Sensitive Policy Gradient: An Iteration Complexity Analysis](https://mlsanity.com/paper/2403.08955/) (2024)
- [Pessimism Meets Risk: Risk-Sensitive Offline Reinforcement Learning](https://mlsanity.com/paper/2407.07631/) (2024)
- [Recursive Entropic Risk Optimization in Discounted MDPs: Sample Complexity Bounds with a Generative Model](https://mlsanity.com/paper/2506.00286/) (2025)
- [RASR: Risk-Averse Soft-Robust MDPs with EVaR and Entropic Risk](https://mlsanity.com/paper/2209.04067/) (2022)
- [Non-stationary Risk-sensitive Reinforcement Learning: Near-optimal Dynamic Regret, Adaptive Detection, and Separation Design](https://mlsanity.com/paper/2211.10815/) (2022)

## Abstract (arXiv)

We study risk-sensitive reinforcement learning in episodic Markov decision processes with unknown transition kernels, where the goal is to optimize the total reward under the risk measure of exponential utility. We propose two provably efficient model-free algorithms, Risk-Sensitive Value Iteration (RSVI) and Risk-Sensitive Q-learning (RSQ). These algorithms implement a form of risk-sensitive optimism in the face of uncertainty, which adapts to both risk-seeking and risk-averse modes of exploration. We prove that RSVI attains an tildeObig(λ(|β| H2) · √H3 S2AT big) regret, while RSQ attains an tildeObig(λ(|β| H2) · √H4 SAT big) regret, where λ(u) = (e3u-1)/u for u>0. In the above, β is the risk parameter of the exponential utility function, S the number of states, A the number of actions, T the total number of timesteps, and H the episode length. On the flip side, we establish a regret lower bound showing that the exponential dependence on |β| and H is unavoidable for any algorithm with an tildeO(√T) regret (even when the risk objective is on the same scale as the original reward), thus certifying the near-optimality of the proposed algorithms. Our results demonstrate that incorporating risk awareness into reinforcement learning necessitates an exponential cost in |β| and H, which quantifies the fundamental tradeoff between risk sensitivity (related to aleatoric uncertainty) and sample efficiency (related to epistemic uncertainty). To the best of our knowledge, this is the first regret analysis of risk-sensitive reinforcement learning with the exponential utility.
