Knowledge that Transforms

This paper builds a framework for the analysis of macroeconomic fluctuations that incorporates the endogenous determination of the number of producers and products over the business cycle. Economic expansions induce higher entry rates by prospective entrants subject to sunk investment costs. The sluggish response of the number of producers generates a new and potentially important endogenous propagation mechanism for business cycle models. The return to investment determines household saving decisions, producer entry, and the allocation of labor across sectors. Our framework replicates several features of business cycles and predicts procyclical profits even for preference specifications that imply countercyclical markups.

This paper proposes a new mechanism by which country size and international trade affect macroeconomic volatility. We study a model with heterogeneous firms that are subject to idiosyncratic firm-specific shocks, calibrated to data for the 50 largest economies in the world. When the firm size distribution follows a power law with an exponent close to minus one, idiosyncratic shocks to large firms have an impact on aggregate volatility. Smaller countries have fewer firms and, thus, higher volatility. Trade opening makes the large firms more important, thus raising macroeconomic volatility. Trade can increase aggregate volatility by 15–20 percent in some small open economies.

The optimality of tax smoothing is reexamined using frictional labor markets. In a calibrated matching model that generates empirically relevant labor market fluctuations conditional on exogenous fiscal policy, the Ramsey-optimal policy calls for extreme labor tax rate volatility. Purposeful tax volatility induces dramatically smaller, but efficient, fluctuations of labor markets by keeping distortions constant over the business cycle. We relate the results to standard Ramsey theory by developing welfare-relevant concepts of efficiency and distortions based on primitive matching frictions. Although the basic Ramsey principles of “wedge smoothing” and zero intertemporal distortions hold, tax smoothing depends on whether wages are set efficiently.