When industry powered US growth, companies grew by spending on capital investments like factories and machinery. Back in 1975, firms once spent six times more on capital investments than they did on research and development. But as the US shifted toward a services and knowledge-based economy, intangible investments became increasingly important. In 2002, R&D expenditures for the average firm surpassed capital expenditures for the first time. It’s stayed that way since; nowadays, average R&D spending is roughly twice that of capital expenditures.