AI, Human Cognition and Knowledge Collapse

We study how generative AI, and in particular agentic AI, shapes human learning incentives and the long-run evolution of society's information ecosystem.We build a dynamic model of learning and decision-making in which successful decisions require combining shared, community-level general knowledge with individual-level, context-specific knowledge; these two inputs are complements.Learning exhibits economies of scope: costly human effort jointly produces a private signal about their own context and a "thin" public signal that accumulates into the community's stock of general knowledge, generating a learning externality.Agentic AI delivers context-specific recommendations that substitute for human effort.By…