This paper shows that a search and matching model with idiosyncratic training cost shocks can explain the asymmetric movement of the job-finding rate over the business cycle and the decline of matching efficiency in recessions. Large negative aggregate shocks move the hiring cutoff into a part of the training cost distribution with higher density. The position of the hiring cutoff in the distribution is disciplined by the empirical elasticity of the job-finding rate with respect to market tightness. Our model explains a large fraction of the matching efficiency decline during the Great Recession and generates state-dependent effects of policy interventions.

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.

Interest in business cycles has had its 'ups and downs'. After a period of almost steady state growth and of economic tranquility, when the business cycle seemed to be obsolete, the turbulence of the 70s and 80s has contributedto a renewed interest in the topic. Important analytical and methodological innovations have also favored the present abundance of contributions. Four innovations are of particular importance: i. microfoundations ii. nonlinearities iii. stochastic variables iv. real aspects. Both Classical macroeconomics and new-Keynesian approaches seem to share these characteristics, which apply both to endogenous and exogenous explanations of the cycle. The distance separating the newer literature from its forebears seems vast. Previously, cycle theory was characterized by a macro approach and utilized nonlinearities either through piecewise 'linear models or with the aid of Classical theorems in the field of dynamic systems. To consider and to compare the old and the new literature on business cycles is one of the goals of this book. To narrow the distance separating them is another goal of this research. We do not try to bridge it, but rather to revisit the former tradition with new tools. Finally, a particular emphasis is put on the 'ceilings and floors' type of literature. One of us has written a D. Phil. thesis with Sir John Hicks, and both have worked with H. P. Minsky. Hicks, along with Goodwin, introdu. ced the concept of ceilings and floors into business cycle analysis, and Minsky made important contributions to the area.

Traditionally, economic growth and business cycles have been treated independently. However, the dependence of GDP levels on its history of shocks, what economists refer to as “hysteresis,” argues for unifying the analysis of growth and cycles. In this paper, we review the recent empirical and theoretical literature that motivate this paradigm shift. The renewed interest in hysteresis has been sparked by the persistence of the Global Financial Crisis and fears of a slow recovery from the Covid-19 crisis. The findings of the recent literature have far-reaching conceptual and policy implications. In recessions, monetary and fiscal policies need to be more active to avoid the permanent scars of a downturn. And in good times, running a high-pressure economy could have permanent positive effects.

Business cycle fluctuations in the U.S. employment-to-population ratio are asymmetric: deviations below trend (troughs) are larger than deviations above trend (peaks). This asymmetry has a "scarring effect," which reduces the average level of the employment-to-population ratio around which the economy fluctuates. To quantify such a scar, we formulate an equilibrium business cycle model featuring frictional unemployment and a labor force participation choice that produces the observed labor market asymmetry in the face of symmetric business cycle shocks. We quantify that the employment-to-population ratio would be 0.3 percentage points higher in the absence of cyclical fluctuations. Further, by dampening business cycles, counter-cyclical stabilization policy reduces the job loss by 70%.