A theoretical and empirical examination of wage differentials findsthat traditional theories of competition do not explain why workers with identical skills are paid differently.

This book focuses on the modeling of the transitions in and out of unemployment, given the stochastic processes that break up jobs and lead to the formation of new jobs, and on the implications of this approach for macroeconomic equilibrium and for the efficiency of the labor market. An equilibrium theory of unemployment assumes that firms and workers maximize their payoffs under rational expectations and that wages are determined to exploit the private gains from trade. This book focuses on the modeling of the transitions in and out of unemployment, given the stochastic processes that break up jobs and lead to the formation of new jobs, and on the implications of this approach for macroeconomic equilibrium and for the efficiency of the labor market. This approach to labor market equilibrium and unemployment has been successful in explaining the determinants of the "natural" rate of unemployment and new data on job and worker flows, in modeling the labor market in equilibrium business cycle and growth models, and in analyzing welfare policy. The second edition contains two new chapters, one on endogenous job destruction and one on search on the job and job-to-job quitting. The rest of the book has been extensively rewritten and, in several cases, simplified.

Labor Markets and Business Cycles integrates search and matching theory with the neoclassical growth model to better understand labor market outcomes. Robert Shimer shows analytically and quantitatively that rigid wages are important for explaining the volatile behavior of the unemployment rate in business cycles. The book focuses on the labor wedge that arises when the marginal rate of substitution between consumption and leisure does not equal the marginal product of labor. According to competitive models of the labor market, the labor wedge should be constant and equal to the labor income tax rate. But in U.S. data, the wedge is strongly countercyclical, making it seem as if recessions are periods when workers are dissuaded from working and firms are dissuaded from hiring because of an increase in the labor income tax rate. When job searches are time consuming and wages are flexible, search frictions--the cost of a job search--act like labor adjustment costs, further exacerbating inconsistencies between the competitive model and data. The book shows that wage rigidities can reconcile the search model with the data, providing a quantitatively more accurate depiction of labor markets, consumption, and investment dynamics. Developing detailed search and matching models, Labor Markets and Business Cycles will be the main reference for those interested in the intersection of labor market dynamics and business cycle research.

Simple models of urban search matching -- Extensions of urban search-matching models -- Non-monocentric cities and search-matching -- Simple models of urban efficiency wages -- Extensions of urban efficiency wage models -- Non-monocentric cities and efficiency wages -- The spatial mismatch hypothesis : a search-matching approach -- The spatial mismatch hypothesis : an efficiency-wage approach -- Peer effects, social networks, and labor market outcomes in cities -- General conclusion -- Appendix A: basic urban economics -- Appendix B: Poisson process and derivation of Bellman equations -- Appendix C: The Harris-Todaro model.