Anthropic says analysts followed their agent's hidden lean on 86% of open decisions
Anthropic published a study on 27 October 2026 of 50 analysts who used Claude Code, running Claude Opus 4.8, on a farm-cooperative analysis with four open choices, such as which comparison method to use. A coin flip, hidden from the analyst, set which option the agent argued for. Analysts ended up with the agent's option on 86% of the choices. About 50% would mean the agent made no difference.
Why it matters: A manager's sign-off is an independent check only if the signer formed their own view. Afterwards, Anthropic reports, 77% of analysts repeated the agent's argument in at least one answer and 15% credited the agent. Those who followed every lean were about as confident (71 out of 100) as the rest (73), so a reviewer who feels sure tells you little.
The catch: Anthropic strengthened the agent's preferences on purpose, tested one task with one model, and used analysts new to farming. Where analysts had stated a view first, they switched 60% of the time when the agent disagreed and 6% when it agreed; that rests on 38 cases, with a 95% confidence interval of 24 to 82 points. The agent also helped: 3 of 50 agent users made serious methodological errors, against 6 of 11 without it, though Anthropic says the groups are not comparable.
What to do: Before a reviewer opens the agent's recommendation on a decision that moves money, such as a vendor switch or a pricing change, have them write down their answer to the two or three judgment calls. Compare the two afterwards and log where they differ. Anthropic did not test this fix; it is our suggestion, built on its finding.
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