AI coding agents raise code volume but not firm-level software output

Key points

• Harvard study of 700+ software firms, using Jellyfish data from 2021 to March 2026, links AI coding agents to more code but no measurable output gain.
• Agent introduction raised lines of code 30%, commits 20% and pull requests 23%, while Jira issue resolution rates did not change significantly.
• Average code review time rose 49% after agents arrived, and the share of pull requests needing changes nearly doubled, according to the researchers.

Why it matters for marketers: Marketing and content teams using AI to speed production should budget for longer review cycles, since faster drafting may not shorten total delivery time.