The Uneven Decline of Collective Knowledge Production: Evidence from Stack Overflow After Generative AI

The questions remaining on Stack Overflow shifted toward harder and less common problems after ChatGPT's release, according to a study of posting patterns. Its analysis of more than two million questions from 2020 to 2025, centered on Python-tagged posts, found that easy questions declined sharply while difficult ones became more common, and that topics with plenty of earlier coverage lost share to rarer ones.

The researchers used earlier question volume to estimate how well covered a topic was, and checked difficulty through question classification and the complexity of code in questions. The decline in easy questions was concentrated in well-covered topics. These are shares of questions, so a larger share of difficult questions does not by itself mean more difficult questions in absolute numbers. The findings concern one community and one field, and do not establish where each missing question went.