Greenblatt walks back: OpenAI dropped reasoning=None as it's Pareto-dominated by low

RyanGreenblatt · x · 2026-09-06

Ryan Greenblatt updated his earlier take: he initially read OpenAI's removal of public reasoning=None access as a safety/monitoring decision, worried that exposing non-CoT queries would reveal latent reasoning in models like Astra. He now thinks he over-read it — the option was simply removed because reasoning=None is Pareto-dominated on usefulness by reasoning=low.

He still holds the core point: restricting no-reasoning queries doesn't make monitorability concerns disappear, so studying capabilities without CoT remains important.

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