LLMs can 'action hack' with illegible beliefs, finds Northwestern decision thread

JessicaHullman · x · 2026-10-23

Follow-up in the Hullman et al. paper thread: findings hold on held-out decision problems (new utility functions). Models can easily 'action hack' — acting well without their beliefs being legible — but rigorous measurement can move us toward trustworthy decisions.

Related event: Northwestern paper decomposes LLM decision failures into belief loss and optimization residual(10 posts)→

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