A new BIS paper by Gambacorta, Qiu, Shan and Rees finds that generative AI increases coder output by more than 50%, but that productivity gains are only statistically significant among entry-level/junior staff. In part, this reflects less frequent use of gen AI by senior programmers. This suggests that while generative AI can boost productivity, its adoption and usage patterns differ greatly based on experience levels. This highlights the importance of tailored strategies to maximize the benefits of AI across varying seniority levels in the workforce.