Before starting tasks, developers forecast that allowing AI will reduce completion time by 24%. After completing the study, developers estimate that allowing AI reduced completion time by 20%. Surprisingly, we find that allowing AI actually increases completion time by 19%—AI tooling slowed developers down. This slowdown also contradicts predictions from experts in economics (39% shorter) and ML (38% shorter).
This report made the rounds. the aha study showing a slowdown. But here’s my take.
- This study did not include CLI, only cursor. So you had both a retooling expense and frankly early 2025 is still very new for coding agents.
- Open Source software is notoriously slow by design. And frankly as soon as any committee driven process detects something new it slows down to a fault.
I think in short. They should continue to measure productivity in this manner and see how things evolve over time. No amount of its 20% slower overall replaces the FOMO happening on boards right now.
Quote Citation: Joel Becker, Nate Rush, Beth Barnes, David Rein, “Measuring the Impact of Early-2025 AI on Experienced Open-Source Developer Productivity”, Jul 25 2025, https://arxiv.org/pdf/2507.09089