Is productivity growth coming from working harder or working smarter?
Core argument: Capital utilization and capital deepening are distinct mechanisms, but firms pushing existing assets harder typically accelerate capex simultaneously, linking near-term utilization gains to longer-run investment cycles.
What appears to be lifting US labor productivity, rather than microproductivity gains, are macroproductivity gains from AI—specifically companies running their existing capital harder. Think longer runs of factories already built, more utilization of server racks and GPU clusters already paid for, and more occupancy of existing hotel rooms. Economists call this “capital intensity” or “utilization.” Higher capital utilization represents real economic gains, but it’s not the same as microproductivity. This is not the same as “capital deepening” (growth in measured productivity from expanding capital supply—for example, through capital investment). What the current numbers do not yet support is the claim that this transmission is already well underway at the aggregate level: adoption is too thin, the cross-sectional signal is too weak, downstream bottlenecks remain, and the productivity pickup is too attributable to utilization to be confident in that conclusion. Instead, the acceleration we’re seeing so far is largely a result of companies trying to meet the demand for AI capacity by pushing the limits of their existing infrastructure.