Is weak business investment driven by labor supply rather than AI competition?
Core argument: The Wicksellian spread between return on capital and cost of capital remains positive, contrasting with the late 1990s tech boom.
Outside AI, business capex was anemic, contributing just 1.54% to total capex growth—a share that has barely been exceeded for the last two years. While investment is clearly attracting a lot of financial and real resources, the crowding-out thesis does not stand up well to scrutiny. If the demand for capital generated by AI investment were really pricing other projects out of the market, then the real cost of borrowed capital would have increased materially. That is what happened in the tech boom of the late 1990s. But this time around, the “Wicksellian spread” between return on capital and cost of capital has remained positive. The US corporate sector has abundant internally generated funds for capex. The US nonfinancial corporate financing gap—the difference between capex and gross savings—is negative. This suggests that businesses are not investing beyond their means, and therefore are not forced to pick and choose between investment opportunities. US businesses have enough financial capacity to invest both in AI and non-AI projects. The tightening of immigration policy under Donald Trump has brought US labor force growth (and population growth) almost to a standstill. This implies slower consumer demand growth and less incentive for business capex.

