Although employment at individual firms tends to be highly nonstationary, 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 review surveys general...

This paper adds imitation by incumbent firms, and not just by new entrants, to the model of selection and growth developed in Luttmer [2007]. Noisy firm-level innovation and imitation give rise to a long-run growth rate that exceeds the average rate at which individual firms innovate. It can be...

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...

Consider an economy in which various types of labor are used to produce consumption, but not all types of labor are useful for upgrading the stock of organization capital–that is, for replacing old projects with more productive new projects. When news induces consumers to want to save more,...

This paper describes a model of search unemployment in an economy with multi-worker firms. It combines competitive labor market search with the model of firm growth of Luttmer [2011]. In a baseline version, Gibrat's law holds approximately and aggregate shocks that destroy blueprint capital...

This paper describes a simple model of aggregate and firm growth based on the introduction of new goods. An incumbent firm can combine labor with blueprints for goods it already produces to develop new blueprints. Every worker in the economy is also a potential entrepreneur who can design a new...

This paper presents an analytically tractable model in which firm dynamics is driven by technology adoption and fixed costs. Existing firms experience idiosyncratic changes in technology. On average, the rate of technological progress among existing firms is slower than that of the frontier...