The Pareto-like tail of the size distribution of firms can arise from random growth of productivity or stochastic accumulation of capital. If the shocks that give rise to firm growth are perfectly correlated within a firm, then the growth rates of small and large firms are equally volatile, contrary to what is found in the data. If firm growth is the result of many independent shocks within a f...

The history of a number of industries is marked by a succession of eras, associated with different dominant technologies. Within any era, industry concentration tends to grow. Particular eras are broken by the introduction of a new technology which, while initially inferior to the established one in the prominent uses, has the potential to become competitive. In many case new entrants survive a...

The history of a number of industries is marked by a succession of eras, associated with different dominant technologies. Within any era, industry concentration tends to grow. Particular eras are broken by the introduction of a new technology which, while initially inferior to the established one in the prominent uses, has the potential to become competitive. In many case new entrants survive a...