This paper develops the view that workers move into and out of the labor market because of changes in the perceived value of their market opportunities. A search model is combined with a matching model to yield movement of workers from job to job and into and out of employment.

This paper develops the view that workers move into and out of the labor market because of changes in the perceived value of their market opportunities. A search model is combined with a matching model to yield movement of workers from job to job and into and out of employment.

This is a paper on expected inflation and welfare in steady-state equilibrium. The demand for money is an inventory demand with an endogenous payment period--the Clower constraint is not imposed. Higher inflation reduces welfare by reducing consumption, as people devote more of their real income to maintaining lower average money holdings. High inflation does not necessarily promote an increase in the capital stock--the Mundell-Tobin effect is absent. The policy conclusion is standard: deflate at the rate of time preference. Because capital is held, socially optimal consumption falls short of its golden-rule level. If inside money is allowed, it drives out fiat money, and welfare is again at a maximum.

This is a paper on expected inflation and welfare in steady-state equilibrium. The demand for money is an inventory demand with an endogenous payment period--the Clower constraint is not imposed. Higher inflation reduces welfare by reducing consumption, as people devote more of their real income to maintaining lower average money holdings. High inflation does not necessarily promote an increase in the capital stock--the Mundell-Tobin effect is absent. The policy conclusion is standard: deflate at the rate of time preference. Because capital is held, socially optimal consumption falls short of its golden-rule level. If inside money is allowed, it drives out fiat money, and welfare is again at a maximum.

A long-run equilibrium theory of turnover is presented and is shown to explain the important regularities that have been observed by empirical investigators. A worker's productivity in a particular job is not known ex ante and becomes known more precisely as the worker's job tenure increases. Turnover is generated by the existence of a nondegenerate distribution of the worker's productivity across different. The nondegeneracy is caused by the assumed variation in the quality of the worker-employer match.

This is a model of permanent job separations when there are endogenous firm-specific human capital and intensity of on-the-job search. The result is a combination of human-capital theory with the theory of search turnover and search unemployment. An interesting technical twist is that the worker's decision problem under uncertainty is solved by means of the deterministic maximum principle.

This is a model of permanent job separations when there are endogenous firm-specific human capital and intensity of on-the-job search. The result is a combination of human-capital theory with the theory of search turnover and search unemployment. An interesting technical twist is that the worker's decision problem under uncertainty is solved by means of the deterministic maximum principle.

A long-run equilibrium theory of turnover is presented and is shown to explain the important regularities that have been observed by empirical investigators. A worker's productivity in a particular job is not known ex ante and becomes known more precisely as the worker's job tenure increases. Turnover is generated by the existence of a nondegenerate distribution of the worker's productivity across different. The nondegeneracy is caused by the assumed variation in the quality of the worker-employer match.

We study the effects of parameter uncertainty prompted by structural breaks. In our model, agents respond differently to uncertainty prompted by regime shifts in shock processes than they react to comparable perceived increases in shock volatility. The magnitude of the response to an increase in uncertainty about TFP associated with a structural break is greater than that of a response to a comparable perceived rise in volatility. This is because lifetime utility varies more when shocks shift beliefs and perceived wealth.

This paper analyzes a decentralized process for the diffusion of knowledge. In equilibrium, the economy converges from an initial distribution of knowledge over agents to the steady-state distribution, which is unique. Because of the public good aspect of information, too little learning takes place, and ideas are implemented too early. The key difference between earlier formulations of search externalities by Diamond, Mortensen, and Spence on the one hand, and our own on the other, is that here spillovers of knowledge depend not only on how hard people are trying, but also on the differences in what they know: if all of us know the same thing, we cannot learn from each other. The model also addresses the following two substantive questions: first, the relationship between inequality and growth, noted some time ago by Kuznets, and second, the effect on growth of improvements in the communication technology.