Most firms begin very small, and large firms are the result of typically decades of persistent growth. This growth can be understood as the result of some form of capital accumulation—-organization capital. In the US, the distribution of firm size k has a right tail only slightly thinner than 1/k. This means that most capital accumulation must be accounted for by incumbent fi…rms. This paper describes a range of circumstances in which this implies aggregate convergence rates that are only about half of what they are in the standard Cass-Koopmans economy. Through the lens of the models described in this paper, the aftermath of the Great Recession of 2008 is unsurprising if the events of late 2008 and early 2009 are interpreted as a destruction of organization capital.

This paper presents a simple formula that relates the tail index of the firm size distribution to the aggregate speed with which an economy converges to its balanced growth path. The fact that there are so many firms in the right tail implies that aggregate shocks that permanently destroy employment among incumbent firms, rather than cause these firms to scale back temporarily, are followed by slow recoveries. This is true despite the presence of many rapidly growing firms. Aggregate convergence rates are non-linear: they can be very high for economies far below the balanced growth path and very low for advanced economies.

Although employment at individual firms tends to be highly non-stationary, the employment size distribution of all firms in the United States appears to be stationary. It closely resembles a Pareto distribution. There is a lot of entry and exit, mostly of small firms. This paper surveys general equilibrium models that can be used to interpret these facts and explores the role of innovation by new and incumbent firms in determining aggregate growth. The existence of a balanced growth path with a stationary employment size distribution depends crucially on assumptions made about the cost of entry. Some type of labor must be an essential input in setting up new firms.

Most firms begin very small, and large firms are the result of typically decades of persistent growth. This growth can be understood as the result of some form of organization capital accumulation. In the US, the distribution of firm size k has a right tail only slightly thinner than 1/k. This is shown to imply that incumbent firms account for most aggregate organization capital accumulation. And it implies potentially extremely slow aggregate convergence rates. A benchmark model is proposed in which managers can use incumbent organization capital to create new organization capital. Workers are a specific factor for producing consumption, and they require managerial supervision. Through the lens of the model, the aftermath of the Great Recession of 2008 is unsurprising if the events of late 2008 and early 2009 are interpreted as a destruction of organization capital, or as a belief shock that made consumers want to reduce consumption and accumulate more wealth instead.