انتشار چرخه کسب و کار درون زا و تداوم مشکلات : نقش اصطکاک بازار کار

Contrasting sharply with a recent trend in DSGE modeling, we propose a business cycle model where frictions and shocks are chosen with parsimony. The model emphasizes a few labor-market frictions and shocks to monetary policy and technology. The model, estimated from U.S. quarterly postwar data, accounts well for important differences in the serial correlation of the growth rates of aggregate quantities, the size of aggregate fluctuations and key comovements, including the correlation between hours and labor productivity. Despite its simplicity, the model offers an answer to the persistence problem (Chari et al., 2000) that does not rely on multiple frictions and adjustment lags or ad hoc backward-looking components. We conclude modern DSGE models need not embed large batteries of frictions and shocks to account for the salient features of postwar business cycles.

A recent trend in dynamic stochastic general equilibrium (DSGE) modeling has seen frictions and shocks proliferate to improve the fit of macro models.1 This modeling strategy has been prone to criticism. Among the new frictions, some like the rule-of-thumb behavior of price-setters and the backward indexing of wages and prices lack a convincing microfoundation (Woodford, 2007 and Cogley and Sbordone, 2008), whereas of the many shocks now driving these models, some are dubiously structural and do not have a clear economic interpretation (Chari et al., 2009).2 But do DSGE models really need to rely on heavy batteries of frictions and shocks to account for the salient features of the postwar U.S. business cycle? The answer we provide in this paper is no.

This paper has proposed a parsimonious approach to study business cycle dynamics. It differs sharply from the recent trend in DSGE modeling which has seen the number of frictions and shocks increase considerably to improve the fit of macro models. We have offered evidence showing that the interactions between sticky wages, costly labor adjustment and monetary policy have several important macroeconomic implications. It helps account for important differences in the dynamics of employment, output, consumption and investment growth. It is also consistent with the actual size of aggregate fluctuations and several key comovements, including that between hours and productivity.