This paper accounts for the observed increase in unemployment duration relative to the unemployment rate in the U.S. over the past thirty years, typified by the record low level of short-term unemployment. We show that part of the increase is due to changes in how duration is measured, a...

This paper extends Lucas and Prescott's (1974) search model to develop a notion of rest unemployment. The economy consists of a continuum of labor markets, each of which produces a heterogeneous good. There is a constant returns to scale production technology in each labor market, but labor...

This paper argues that a broad class of search models cannot generate the observed business-cycle-frequency fluctuations in unemployment and job vacancies in response to shocks of a plausible magnitude. In the U.S., the vacancy-unemployment ratio is 20 times as volatile as average labor...

We survey search-theoretic models of the labor market and discuss their usefulness for analyzing labor market dynamics, job turnover, and wages. We first examine single-agent models, showing how they can incorporate many interesting features and generate rich predictions. We then consider...

This paper uses readily accessible data to measure the probability that an employed worker becomes unemployed and the probability that an unemployed worker finds a job, the ins and outs of unemployment. Since 1948, the job finding probability has accounted for three-quarters of the fluctuations...

This paper measures the job-finding, separation, and job-to-job transition rates in the United States from 1948 to 2004. The job-finding and job-to-job transition rates are strongly procyclical and the separation rate is nearly acyclical, especially since 1985. The author develops a simple model...

The standard theory of equilibrium unemployment, the Mortensen-Pissarides search and matching model, cannot explain the magnitude of the business cycle fluctuations in two of its central elements, unemployment and vacancies. Modifying the model to make the present value of wages unresponsive to...

This paper develops a dynamic model of mismatch. Workers and jobs are randomly assigned to labor markets. Each labor market clears at each instant but some labor markets have more workers than jobs, hence unemployment, and some have more jobs than workers, hence vacancies. As workers and jobs...

Daron Acemoglu, winner of the 2005 John Bates Clark Medal, uses theoretical and empirical analysis to tackle critical issues in a variety of fields in economics, including labor economics, macroeconomics, and political economy. His unparalleled combination of originality, thoroughness, and...