Economists Daron Acemoglu, David Autor and Christina Patterson argue that AI’s productivity gains may be modest. That history suggests AI’s diffusion may likewise deliver less transformative productivity growth than its most enthusiastic advocates expect. The financial strain of the AI infrastructure raceOver the past two years, Big Tech’s financial model has undergone a profound shift. Historical evidence, notably from the Jordà-Schularick-Taylor Macrohistory Database, shows that crises are far more damaging when credit growth and asset bubbles coincide. Sectoral focus amplifies this concentration risk: AI data centers and related infrastructure dominate the current private credit pipeline.