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 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...

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 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...

This paper studies the assignment of heterogeneous workers to heterogeneous jobs in the presence of coordination frictions. Firms offer human-capital-contingent wages, workers observe these and apply for a job. In a symmetric equilibrium, identical workers use identical mixed strategies in...

We develop a random search model with two-sided heterogeneity and match-specific productivity shocks to explain why high-productivity workers tend to work at high-productivity firms despite low-productivity workers gaining about as much from such matches. Our model has two key predictions: i)...

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...

For an incompatible patient-donor pair, kidney exchanges often forbid receipt-before-donation (the patient receives a kidney before the donor donates) and donation-before-receipt, causing a double-coincidence-of-wants problem. Our proposed algorithm, the Unpaired kidney exchange algorithm, uses...

We develop a dynamic model of transitions in and out of employment. A worker finds a job at an optimal stopping time, when a Brownian motion with drift hits a barrier. This implies that the duration of each worker's jobless spells has an inverse Gaussian distribution. We allow for arbitrary...

We study pairwise trading mechanisms in the presence of private information and limited commitment, whereby either trader can walk away from a proposed trade when he learns the trading price. We show that when one trader's information is relevant for the other trader's value of the asset,...