AI and the Quantity and Quality of Creative Products: Have LLMs Boosted Creation of Valuable Books?

The diffusion of LLMs from 2022 to 2025 tripled new book releases. While average book quality, measured by usage, declined, the surge in releases raised the number of modest-quality books. Direct evidence using AI detection shows that AI-containing books have lower quality, and their rising share – topping half of 2025 releases – drives the overall decline. A nested logit calibration shows that AI books raised consumer surplus by seven percent in 2025. Author selection accounts for most of the AI quality differential, and the AI-human differential shrinks over time. Finally, AI has not displaced authors active prior to LLMs.