Social Cost of Cognitive Displacement

When a factory burns coal, the smoke costs someone. The factory pays for iron, labor, and fuel; it does not pay for the damaged lungs, the corroded buildings, the disrupted climate. Arthur Cecil Pigou called this gap an externality, and William Nordhaus spent four decades calculating its magnitude in the form of the social cost of carbon—the total damage that one additional ton of emissions imposes on the global economy. The same analytical structure applies to artificial intelligence. When a firm deploys an AI system that performs work previously done by humans, the private benefit is clear: the AI is cheaper, faster, and often more consistent. But the private benefit does not capture the full social cost. The displaced worker bears stranded human capital. The educational system bears the cost of curricula whose economic value has been disrupted. The profession bears the erosion of its apprenticeship pipeline. The future generation bears a world with fewer practiced human