Firms that entered the stock market in the 1990s were younger than any earlier cohort since World War I. Surprisingly, however, firms that IPO'd at the close of the 19th century were just as young as the companies that are entering today. We argue here that the electrification-era and the IT-era...

A new technology or product is often developed by the single entrepreneur. Whether he reaches the public offering stage or is acquired by a listed firm it takes time for the innovator to add value to the stock market. Indeed first, reduce the market's value because some firms -- usually large or...

In a growth model, rent-grabbing and free riding can give rise to inequality in productivity and firm size. Inequality among firms affects a firm's incentive to free ride or to grab rents, and, hence, the incentive to invest in research and training We follow Lucas and Prescott (1971) and...

A satisfactory account of the postwar growth experience of the United States should be able to come to terms with the following three facts: 1. Since the early 1970's there has been a slump in the advance of productivity. 2. The price of new equipment has fallen steadily over the postwar period....

Machines are more expensive in poor countries, and the relation is pronounced. It is hard for a Solow (1956) type of model to explain the relation between machine prices and GDP given that in most countries equipment investment is under 10% of GDP. A stronger relation emerges in a Solow (1959)...

This paper deals with processes that require several complementary inputs subject to improvements in quality. If after a quality upgrade one of these inputs requires a period of learning before it can be used effectively, then in general it will pay to purchase the inputs at different dates --...

People at the top of an occupational ladder earn more partly because they have spent time on lower rungs, where they have learned something. But what precisely do they learn? There are two contrasting views: First, the Bandit model assumes that people are different, that experience reveals their...

We analyze the contractual relation between workers and their employers when there is nominal risk. The key feature of the problem is that the consumption deflator is random and observed sometime after the effort is exerted. The worker's effort is not observable, and to induce the agent to work,...

We model research as a signal on an unknown parameter of a technology. We distinguish applied from basic research and show that firms in the same industry can optimally choose different research portfolios, and that basic research can seem to have a higher rate of return than applied research,...

Most of our productive knowledge was handed down to us by previous generations. The transfer of knowledge from the old to the young is therefore a cornerstone of productivity growth. We study this process in a model in which the old sell knowledge to the young - - old workers train the young,...