Investment in intangible capital--in particular, research and development--increased dramatically since the 1990s. However, productivity growth remains sluggish in recent years. One potential reason is that a significant share of the increase in intangible investment is geared toward consumer...

We propose a model that starts from the premise that intangible capital needs to be stored on some medium --- software, patents, essential employees --- before it can be utilized in production. Storage implies that intangible capital may be partially non-rival within the firm, leading to scale...