Research Database

Real business cycles are recurrent fluctuations in an economy’s incomes, products, and factor inputs—especially labor—that are due to nonmonetary sources. These sources include changes in technology, tax rates and government spending, tastes, government regulation, terms of trade, and energy prices. Most real business cycle (RBC) models are variants or extensions of a neoclassical growth model. One such prototype is introduced. It is then shown how RBC theorists, applying the methodology of Kydland and Prescott (Econometrica 1982), use theory to make predictions about actual time series. Extensions of the prototype model, current issues, and open questions are also discussed.

Unionism in the United States is contagious; it spills out of coal mines and steel mills into other establishments in the neighborhood, like hospitals and supermarkets. The geographic spillover of unionism is documented here using a newly constructed establishment level data on unionism that is rich in geographic detail. A strong connection is found between unionism of health care establishments today and proximity to unionized coal mines and steel mills from the 1950s.

This paper proposes an aggregative model of Total Factor Productivity (TFP) in the spirit of Houthakker (1955–1956). It considers a frictional labor market where production units are subject to idiosyncratic shocks and jobs are created and destroyed as in Mortensen and Pissarides (1994). An aggregate production function is derived by aggregating across micro production units in equilibrium. The level of TFP is explicitly shown to depend on the underlying distribution of shocks as well as on all the characteristics of the labor market as summarized by the job-destruction decision. The model is also used to study the effects of labor-market policies on the level of measured TFP.

We develop a model of gross job and worker flows and use it to study how the wages, permanent incomes, and employment status of individual workers evolve over time. Our model helps explain various features of labor markets, such as the amount of worker turnover in excess of job reallocation, the length of job tenures and unemployment duration, and the size and persistence of the changes in income that workers experience due to displacements or job-to-job transitions. We also examine the effects that labor market institutions and public policy have on the gross flows, as well as on the resulting wage distribution and employment in the equilibrium. From a theoretical standpoint, we propose a notion of competitive equilibrium for random matching environments, and study the extent to which it achieves an efficient allocation of resources.

This paper studies the empirical relevance of temptation and self-control using household-level data from the Consumer Expenditure Survey. We estimate an infinite-horizon consumption-savings model that allows, but does not require, temptation and self-control in preferences. To help identify the presence of temptation, we exploit an implication of the theory that a tempted individual has a preference for commitment. In the presence of temptation, the cross-sectional distribution of the wealth-consumption ratio, in addition to that of consumption growth, becomes a determinant of the asset-pricing kernel, and the importance of this additional pricing factor depends on the strength of temptation. The estimates that we obtain provide statistical evidence supporting the presence of temptation. Based on our estimates, we explore some quantitative implications of this class of preferences on equity premium and on the welfare cost of business cycles.

We propose a simple method to help researchers develop quantitative models of economic fluctuations. The method rests on the insight that many models are equivalent to a prototype growth model with time-varying wedges which resemble productivity, labor and investment taxes, and government consumption. Wedges corresponding to these variables—efficiency, labor, investment, and government consumption wedges—are measured and then fed back into the model in order to assess the fraction of various fluctuations they account for. Applying this method to U.S. data for the Great Depression and the 1982 recession reveals that the efficiency and labor wedges together account for essentially all of the fluctuations; the investment wedge plays a decidedly tertiary role, and the government consumption wedge, none. Analyses of the entire postwar period and alternative model specifications support these results. Models with frictions manifested primarily as investment wedges are thus not promising for the study of business cycles. (See Additional Material for a response to Christiano and Davis (2006).)

The common approach to evaluating a model in the structural VAR literature is to compare the impulse responses from structural VARs run on the data to the theoretical impulse responses from the model. The Sims-Cogley-Nason approach instead compares the structural VARs run on the data to identical structural VARs run on data from the model of the same length as the actual data. Chari, Kehoe, and McGrattan (2006) argue that the inappropriate comparison made by the common approach is the root of the problems in the SVAR literature. In practice, the problems can be solved simply. Switching from the common approach to the Sims-Cogley-Nason ap-proach basically involves changing a few lines of computer code and a few lines of text. This switch will vastly increase the value of the structural VAR literature for economic theory.

Typical models of bankruptcy and collateral rely on incomplete asset markets. In fact, bankruptcy and collateral add contingencies to asset markets. In some models, these contingencies can be used by consumers to achieve the same equilibrium allocations as in models with complete markets. In particular, the equilibrium allocation in the debt constrained model of Kehoe and Levine (2001) can be implemented in a model with bankruptcy and collateral. The equilibrium allocation is constrained efficient. Bankruptcy occurs when consumers receive low income shocks. The implementation of the debt constrained allocation in a model with bankruptcy and collateral is fragile in the sense of Leijonhufvud’s “corridor of stability,” however: If the environment changes, the equilibrium allocation is no longer constrained efficient.