THE EVIDENCE
This isn't another AI opinion piece.
Every statistic, study and case in the book comes from a published source — peer-reviewed papers, working papers, large employer and worker surveys, court records, medical journals and reputable reporting. Full references are in Notes & Sources.
01RESEARCH FINDING
AI doesn't help everyone equally.
When 5,172 customer-support agents got an AI assistant, the least experienced improved most. The most experienced gained little.
Most experienced & skilledminimal
Brynjolfsson, Li & Raymond, Quarterly Journal of Economics (2025). Issues resolved per hour.
02RESEARCH FINDING
The jagged frontier.
In a study of 758 consultants, AI excelled on some tasks — then quietly failed on a neighbouring one that looked just as easy, sounding equally confident either way.
INSIDE THE FRONTIER
40%+
higher-quality work, 25.1% faster
JUST OUTSIDE IT
−19 pts
less likely to reach the correct answer
Dell'Acqua et al., "Navigating the Jagged Technological Frontier" (Boston Consulting Group study).
03RESEARCH FINDING
Feeling faster isn't being faster.
In a randomised trial, experienced developers expected AI to speed them up. With early-2025 tools, it slowed them down — and they still believed it had helped.
A 2026 follow-up with newer tools points the other way. The book explains both — and why you should measure, not assume.
METR randomised controlled trial, 16 developers, 246 real tasks (July 2025).
04CASE STUDY
Experience alone isn't armour.
In Mata v. Avianca, a lawyer with roughly three decades of practice filed a brief citing court decisions that did not exist. ChatGPT had invented them.
$5,000
fine for lawyers & firm
His experience was real. What he lacked was an understanding of how the tool worked.
Court records, Southern District of New York, June 22, 2023.
05CASE STUDY · RESEARCH FINDING
Automation has hidden costs.
SKILLS THAT FADE
In one contested study of 19 endoscopists, the unaided detection rate fell from 28.4% to 22.4% after AI was introduced. A warning sign, not proof.
THE HUMAN TOUCH
Klarna leaned heavily on an AI assistant for customer service — then began recruiting human staff again after its CEO acknowledged lower quality.
THE PIPELINE
If AI absorbs the routine work beginners learn from, where do tomorrow's experts come from? The book examines the evidence — and its limits.