Qualification: In Gao, Schulman, and Hilton's synthetic proxy-versus-gold reward-model setup, optimizing an imperfect proxy too much can hinder ground-truth performance.

Record: kaal:position:2026-09-26-004 · 2026-09-26

Gao, Schulman, and Hilton show the central Goodhart problem in reward-model optimization: an imperfect proxy can improve under optimization while ground-truth performance worsens. This supports the protected overoptimization claim in their controlled synthetic setup. The result should not be overstated. Their gold-standard reward model stands in for humans, and the abstract does not establish that degradation is monotonic in realized KL distance from the reference policy.

Affirmed commentary position. This record extends a source-bound scholarly claim but is not a verbatim paper claim.
Holds when
Current debate

In Gao, Schulman, and Hilton's synthetic proxy-versus-gold reward-model setup, optimizing an imperfect proxy too much can hinder ground-truth performance.

Scholarly basis

kaal:claim:7456999-016
Wulf A. Kaal, Reinforcement Learning from Reputation Feedback (2026). SSRN: https://ssrn.com/abstract=7456999
Source PDF sha256: 01016fbbcc25cad205cebd59ea686d8dfee8ae9b632095d86ba6c9a900456a4b

Evidence and mapping

Evidence: permitted_full_text
Review tier: independent evidence-first compound-growth review
Mapping confidence: unscored
Mapping ambiguous: false

Topics

ai-and-agentsrisk-and-incentivesempirical-evidence

Provenance

Affirmed in kaal-growth:2026-09-26:daily-001 on 2026-09-26. Review record.

Verify

Canonical markdown sha256: 4223e126645f75f2203300500e9114fdd816c184478be395d3a0be989495fc42
curl -s https://wulfkaal.github.io/positions/2026-09-26-004.md | sha256sum