Julio J. Rotemberg

Bio: Julio J. Rotemberg is an academic researcher from Harvard University. The author has contributed to research in topics: Inflation & Consumption (economics). The author has an hindex of 15, co-authored 33 publications receiving 3976 citations. Previous affiliations of Julio J. Rotemberg include National Bureau of Economic Research & Massachusetts Institute of Technology.

An Optimization-Based Econometric Framework for the Evaluation of Monetary Policy

Abstract: This paper considers a simple quantitative model of output, interest rate and inflation determination in the United States, and uses it to evaluate alternative rules by which the Fed may set interest rates. The model is derived from optimizing behavior under rational expectations, both on the part of the purchasers of goods (who choose quantities to purchase given the expected path of real interest rates), and upon that of the sellers of goods (who set prices on the basis of the expected evolution of demand). Numerical parameter values are obtained in part by seeking to match the actual responses of the economy to a monetary shock to the responses predicted by the model. The resulting model matches the empirical responses quite well and, once due account is taken of its structural disturbances, can account for our data nearly as well as an unrestricted VAR. The monetary policy rule that most reduces inflation variability (and is best on this account) requires very variable interest rates, which in turn is...

Intertemporal Substitution in Macroeconomics

Abstract: Modern neoclassical theories of the business cycle posit that aggregate fluctuations in consumption and employment are the consequence of dynamic optimizing behavior by economic agents who face no quantity constraint. In this paper, we estimate an explicit model :f this type. In particular, we assume that the observed fluctuations correspond to the decisions of an optimizing representative individual. This individual has a stable utility function which is additively separable over time but not necessarily additively separable in consumption and leisure. We estimate three first order conditions which represent three margins on which the individual is optimizing. He can trade off present consumption for future consumption, present leisure for future leisure and present consumption for present leisure. Our results show that the aggregate U.S. data are extremely reluctant to be characterized by a model of this type. Not only are the overidentifying restrictions statistically rejected but, in addition, the estimated utility function is often not concave. Even when it is concave the estimates imply that either consumption or leisure is an inferior good.

An Optimization-Based Econometric Framework for the Evaluation of Monetary Policy: Expanded Version

Abstract: This paper considers a simple quantitative model of output, interest rate and inflation determination in the United States, and uses it to evaluate alternative rules by which the Fed may set interest rates. The model is derived from optimizing behavior under rational expectations, both on the part of the purchasers of goods and upon that of the sellers. The model matches the estimates responses to a monetary policy shock quite well and, once due account is taken of other disturbances, can account for our data nearly as well as an unrestricted VAR. The monetary policy rule that most reduces inflation variability (and is best on this account) requires very variable interest rates, which in turn is possible only in the case of a high average inflation rate. But even in the case of a constrained-optimal policy, that takes into account some of the costs of average inflation and constrains the variability of interest rates so as to keep average inflation low, inflation would be stabilized considerably more and output stabilized considerably less than under our estimates of current policy. Moreover, this constrained-optimal policy also allows average inflation to be much smaller. This version contains additional details of our derivations and calculations, including three technical appendices, not included in the version published in NBER Macroeconomics Annual 1997.

Intertemporal Substitution in Macroeconomics

Abstract: Modern neoclassical business cycle theories posit that the observed fluctuations in consumption and employment correspond to decisions of an optimizing representative individual. We estimate three first-order conditions that represent three tradeoffs faced by such an optimizing individual. He can trade off present for future consumption, present for future leisure, and present consumption for present leisure. The aggregate U. S. data lend no support to this model. The overidentifying restrictions are rejected, and the estimated utility function is often convex. Even when it is concave, the estimates imply that either consumption or leisure is an inferior good.

International adjustment with wage rigidity

Abstract: Two of the puzzling macroeconomic phenomena of the 1970s have been the persistent stagnation in Europe, and the disagreement between the U.S. and Europe on the feasibility of recovery by demand expansion. This paper develops the hypothesis that the source of both the stagnation and the policy differences is money-wage stickiness in the U.S. and real-wage stickiness in Europe and Japan. A real wage which is sticky above its equilibrium level in Europe and Japan would account for stagnation and infeasibility of recovery by demand expansion. The theoretical models are developed in both the one-commodity and two-commodity-bundle cases. The empirical results confirm that in the U.S. the nominal wage adjusts slowly toward equilibrium, while in Germany, Italy, Japan, and the U.K. the real wage adjusts slowly.

The Financial Accelerator in a Quantitative Business Cycle Framework

Abstract: This paper develops a dynamic general equilibrium model that is intended to help clarify the role of credit market frictions in business fluctuations, from both a qualitative and a quantitative standpoint. The model is a synthesis of the leading approaches in the literature. In particular, the framework exhibits a financial accelerator,' in that endogenous developments in credit markets work to amplify and propagate shocks to the macroeconomy. In addition, we add several features to the model that are designed to enhance the empirical relevance. First, we incorporate money and price stickiness, which allows us to study how credit market frictions may influence the transmission of monetary policy. In addition, we allow for lags in investment which enables the model to generate both hump-shaped output dynamics and a lead-lag relation between asset prices and investment, as is consistent with the data. Finally, we allow for heterogeneity among firms to capture the fact that borrowers have differential access to capital markets. Under reasonable parametrizations of the model, the financial accelerator has a significant influence on business cycle dynamics.

The Science of Monetary Policy: A New Keynesian Perspective

Abstract: This paper reviews the recent literature on monetary policy rules. To organize the discussion, we exposit the monetary policy design problem within a simple baseline theoretical framework. We then consider the implications of adding various real word complications. We concentrate on developing results that are robust across a reasonable variety of competing macroeconomic frameworks. Among other things, we show that the optimal policy implicitly incorporates inflation targeting. We also characterize the gains from making credible commitments to fight inflation and consider the implications of frictions such as imperfect information and model uncertainty. Finally, we assess how proposed simple rules, such as the Taylor rule, square with the principles for optimal policy that we describe. We use this same metric to evaluate the recent course of U.S. monetary policy.

Nominal Rigidities and the Dynamic Effects of a Shock to Monetary Policy

Abstract: We present a model embodying moderate amounts of nominal rigidities that accounts for the observed inertia in inflation and persistence in output. The key features of our model are those that prevent a sharp rise in marginal costs after an expansionary shock to monetary policy. Of these features, the most important are staggered wage contracts that have an average duration of three quarters and variable capital utilization.

The Science of Monetary Policy: A New Keynesian Perspective

Abstract: The paper reviews the recent literature on monetary policy rules. We exposit the monetary policy design problem within a simple baseline theoretical framework. We then consider the implications of adding various real world complications. Among other things, we show that the optimal policy implicitly incorporates inflation targeting. We also characterize the gains from making a credible commitment to fight inflation. In contrast to conventional wisdom, we show that gains from commitment may emerge even if the central bank is not trying to inadvisedly push output above its natural level. We also consider the implications of frictions such as imperfect information.

Monetary policy rules and macroeconomic stability: Evidence and some theory

Abstract: We estimate a forward-looking monetary policy reaction function for the postwar United States economy, before and after Volcker’s appointment as Fed Chairman in 1979. Our results point to substantial differences in the estimated rule across periods. In particular, interest rate policy in the Volcker-Greenspan period appears to have been much more sensitive to changes in expected ineation than in the pre-Volcker period. We then compare some of the implications of the estimated rules for the equilibrium properties of ineation and output, using a simple macroeconomic model, and show that the Volcker-Greenspan rule is stabilizing.