Factimonious®

AI Engineering Economics in a Minute

Cost of Human Review

Why human review is part of AI coding economics—not a free cleanup step after the agent.

In one sentence

The cost of human review is the engineering time (and delay) required to inspect, correct, and approve agent-produced changes.

Why it matters

Agents shift work toward review. Ignoring review cost makes AI look cheaper than the fully loaded workflow.

How it works

  • Estimate review minutes per PR size/risk band.
  • Include re-review after agent follow-up commits.
  • Add opportunity cost when senior engineers become full-time reviewers.
  • Compare against baseline human-authored review cost for similar changes.

Example

A $2 agent patch that needs 45 minutes of senior review at a fully loaded $3/minute internal rate costs far more in review than in tokens. Optimize for reviewability—not only generation speed.

What this proves

Measured review time proves how much human attention a class of agent changes consumed.

What this does not prove

Review time does not prove the change was valuable. Low review time does not prove safety if reviewers are skimming.

Last reviewed 2026-09-06. Title for citation: AI Engineering Economics in a Minute: Cost of Human Review.