METR follow-up study reverses the 19% slowdown result

Aug 17, 2026 · Issue 3 · 2 sources, 2 articles

In METR's first experiment, 16 experienced developers took 19% longer on 246 tasks with AI in mature projects. According to an analysis of 17 August, the follow-up study flips the sign, so the old figure is out of date.

Who is affected and how

CTO

Interpret productivity claims by task type and codebase maturity rather than relying on a single number.

tech lead

Measure the effect on your own team before committing to a roadmap built on AI tools.

Narrative: More code, but not more delivered software

Sources

• AI productivity: the METR number is out of date | devs groupdevs-group.ch · Aug 17, 2026
• AI Productivity Is Not One Number: Why the Gains Are Real ...leocavalcante.dev · Aug 17, 2026

Machine-generated summary based on the titles and excerpts of the source articles. The facts come from the linked article.