ResearchResearch paperReinforcement Learning1 source · Oct 7, 2026

Safe on Average, Unsafe in the Tail: When Is the Episodic-Cost Tail Controllable?

Safe reinforcement learning seeks policies that maximize return while satisfying constraints on cumulative cost.

Key points

  • In this work, we measure the episodic-cost tail using $CVaR{0.1}$, the average cost of the worst $10%$ of episodes.
  • We classify a policy as tail-safe when $CVaR{0.1}$ is within the safety budget.
  • To identify tail-unsafe policies, we evaluate five standard algorithms on three Safety-Gymnasium navigation tasks.
  • We then examine four constraint families on dense-hazard navigation and assess tail control across four navigation and four locomotion tasks.

Sources (1)

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