We study 114 years of U.S. stock market data and find That there are large cohort effects in stock prices, effects that we label 'organization capital,' That cohort effects grew at a rate of 1.75% per year, That the debt-equity ratio of all vintages declined, That three big technological waves...

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....

If machines are indivisible, a vintage capital model must give rise to income inequality. If new machines are always better than old ones and if society cannot provide everyone with a new machine all of the time, inequality will result. I explore this mechanism in detail. If technology resides...

I generalize a benchmark model of directed technical change to allow innovations and factors of production (here energy resources) to be substitutes or complements. I show that a dominant sector is forever locked-in under substitutability but researchers' market incentives can drive a transition...

Most industries go through a quot;shakeoutquot; phase during which the number of producers in the industry declines. Industry output generally continues to rise, however, which implies a reallocation of capacity from exiting firms to incumbents and new entrants. Thus shakeouts seem to be classic...

The age structure of capital plays an important role in the measurement of productivity. It has been argued that the slowdown in the 1970's can be ascribed to the aging of the stock of capital. In this paper we incorporate the age structure in productivity measurement. A proposition proves that...

This paper develops a dynamic stochastic general equilibrium model with putty-clay technology that incorporates embodied technology, investment irreversibility, and variable capacity utilization. Low short-run capital-labor substitutability native to the putty-clay framework induces the...

We embed the microeconomic decisions associated with investment under uncertainty, capacity utilization, and machine replacement in a general equilibrium model based on putty-clay technology. In the presence of irreversible factor proportions, a mean-preserving spread in the productivity of...

This paper studies optimal investment policies when the production function depends on capital of various vintages. In such an environment it is natural to ask whether the firm will invest in old-vintage capital at all. In this paper I derive such a condition. Predictably, investment in old...