Scott Alexander, curated
← Back to curation

What Happened With Bio Anchors?

Quality
73
Strong
Claude Shift
48
Moderate
RWI
3
of 10

Summary

Retrospective on Ajeya Cotra's 2020 Biological Anchors AI-timelines report: why its premises proved impressively right (the scaling hypothesis, compute-driven progress, 'effective FLOPs', 'time horizons' all entered common parlance and its critics were mostly wrong) yet its headline 2050s AGI date was ~20 years too late. The post-mortem (drawing on Davidson and Croxton/Epoch): Cotra nailed willingness-to-spend and FLOPs/$, ignored training-run length, but badly missed algorithmic progress -- 200%/yr vs her ~30% -- because she anchored on one ImageNet (AlexNet, an easy task) paper and, by her own transparent admission, spent the least time on that parameter. Correcting just that one term yields ~2030, matching current vibes. Revisits the contemporaneous critiques (Yudkowsky's disjunctive 'shorter either way' and Nostalgebraist's 'it all hinges on one or two hand-waved parameters' both 'spiritually correct even if their bottom lines were wrong'), and lands on the forecasting lesson: imperfect models cut both ways (the Safe Uncertainty Fallacy), and the right response to irreducible uncertainty is to seek information and treat forecasts as small updates.

Why this score

Quality 73 · Strong. Strong. A numerate, honest, clarifying forecasting post-mortem -- shows exactly how a model can be right in spirit and method yet wrong in conclusion because of one mis-estimated parameter, and extracts a durable epistemics lesson. Held mid-Strong because it is a retrospective synthesis on a single case rather than a field-defining contribution.

Claude’s paradigm shift 48 · Moderate. Moderate. The substance (sensitivity analysis matters; one parameter can dominate; uncertainty is symmetric) is standard forecasting wisdom well-applied, not a new frame. Mild credit for the clean Safe-Uncertainty-Fallacy callback.

Real-world impact 3 · Moderate. Moderate. A reference point in the AI-timelines/forecasting discourse, reinforcing the 'do real sensitivity analysis' norm; conceptual, no material reach. 3.