trailMETR's measured AI slowdown is robust across alternative statistical estimators and empirical strategies
Using AI tools caused experienced open-source developers to complete tasks about 20% slower in early 2025.
METR's 2025 AI slowdown finding generalizes to experienced open-source developers beyond its 16 participants.
METR's 2025 sample of 246 completed issues from 16 developers gave sufficient statistical power to detect AI's effect on developer productivity.
METR's measured AI slowdown remained statistically significant when accounting for developer-level clustering.
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METR's measured AI slowdown estimate was similar across alternative outcome estimators, including a naive ratio estimator
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Differential issue dropout and attrition do not explain METR's measured AI slowdown
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METR's measured AI slowdown is robust across alternative statistical estimators and empirical strategies
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