This post discusses a public METR report on AI R&D acceleration at Anthropic. I did not work on this project or see the unredacted report.1 All opinions are my own and do not represent METR or the report authors.Thanks to Ryan Greenblatt for discussion, feedback, and help with modeling, and Daniel Kokotajlo, Eli Lifland, and Hjalmar Wjik for comments.
Between October 2025 and October 2026, capabilities progress at Anthropic has been going about twice as fast as it had been over the previous twelve months. The measurement they report is an internal version of the Epoch Capabilities Index called AECI; a wide range of other supporting evidence for acceleration has been redacted. They said that this redacted evidence was "a majority of the evidence [they] found most informative."
