What does AI capital spending imply about future economic growth?
Core argument: The five largest U.S. technology firms are scaling AI capital expenditure at roughly 50% per year, from $155 billion in 2022 to a forecast $755 billion in 2026.
The five largest U.S. technology firms are scaling AI capital expenditure at roughly 50% per year, from $155 billion in 2022 to a forecast $755 billion in 2026. This paper embeds this observation in a two-sector model with rare productivity booms to ask what the investment path implies for growth and asset prices. Calibrating the boom size to match the observed investment ramp implies that each boom raises AI-sector productivity by a factor of roughly 2.7. A two-year window of elevated boom probability generates three scenarios: a moderate outcome (one boom only), a transformative outcome (one further boom), and a singularity scenario (two additional booms). Even in the moderate scenario, AI adds ~ 5pp to cumulative GDP growth over the seven-year transition (Figure 2), on top of the ~19% normal-times growth that would otherwise prevail. The transformative and singularity scenarios push the AI contribution to 20% and over 58%, respectively. The non-AI sector continues to grow at its historical rate, [while the] AI sector’s share of the economy rises from ~3% today to btw 8% and 39%, depending on the scenario. As this share grows, the AI sector’s rapid productivity gains increasingly dominate aggregate GDP growth.

