How much do AI coding tools raise code writing versus shipping?
Core argument: AI coding tools raise developer task-level productivity measured by commits by roughly 40% with autocomplete, about 140% cumulatively with synchronous agents, and 180% with asynchronous agents through agent-authored commits.
Our results are summarized in Figure 1. We find that AI coding tools substantially increase developer task-level productivity, with effects that grow across successive generations of tools. Focusing on the number of commits [saved code changes], autocomplete increases task-level productivity by approximately 40%; the cumulative effect including sync agents rises to approximately 140%; and additional use of async agents raises it to 180% through agent authored commits. These effects are larger for less active developers. The results point to a substantial productivity shift in software development with the rise of agentic AI tools. [Yet] our estimates across the layers of the production hierarchy reveal a clear pattern of attenuation. After adopting AI tools, developers write substantially more code and work on more features, but this translates into much smaller increases in shipped software. Sync agents lead to a 741% increase in lines of code and a 65% increase in pull requests, yet releases rise by only 20%. Autocomplete shows the same pattern: a 228% effect on lines of code attenuates to 36% on commits and just 10% on releases. AI tools appear to relax upstream constraints in producing and publishing software, but developers must still test, polish, and iterate toward market fit, and these higher-level tasks may remain constrained [once] AI lowers the cost of writing code.



