Research Database

Measured aggregate U.S. consumption does not behave like a martingale. This paper develops and tests two variants of the permanent income model that are consistent with this fact. In both variants, we assume agents make decisions on a continuous time basis. According to the first variant, the martingale hypothesis holds in continuous time and serial persistence in measured consumption reflects only the effects of time aggregation. We investigate this variant using both structural and atheoretical econometric models. The evidence against these models is far from overwhelming. This suggests that the martingale hypothesis may yet be a useful way to conceptualize the relationship between aggregate quarterly U.S. consumption and income. According to the second variant of the permanent income model, serial persistence in measured consumption reflects the effects of exogenous technology shocks and time aggression. In this model, continuous time consumption does not behave like a martingale. We find little evidence against this variance of the permanent income model. It is difficult, on the basis of aggregate quarterly U.S. data, to convincingly distinguish between the different continuous time models considered in the paper.

The founding fathers of the Econometric Society defined econometrics to be quantitative economic theory. A vision of theirs was the use of econometrics to provide quantitative answers to business cycle questions. The realization of this dream required a number of advances in pure theory—in particular, the development of modern general equilibrium theory. The econometric problem is how to use these tools along with measurement to answer business cycles questions. In this essay, we review this econometric development and contrast it with the econometric approach that preceded it.

This paper analyzes the U.S. congressional proposal to instruct the Federal Reserve to, in the next five years, lower inflation to zero from its current rate of around 5 percent. The paper concludes that, when other policy options are considered, the zero inflation policy is not advisable. Its benefits would be very small—possibly negative—while its costs would probably be significant. Other, more direct policy options could produce most of the same benefits with fewer costs. Among these alternative policies are deregulating interest rates on demand deposits, paying interest on financial institution reserves, lowering the federal tax rate on capital income, and indexing the federal tax code to inflation.

This paper uses a simple general equilibrium model in which agents use money holdings to self insure to address the classic question: What is the optimal rate of change of the money supply? The standard answer to this question, provided by Friedman, Bewley, Townsend, and others, is that this rate is negative. Because any revenues from seigniorage in our model are redistributed in lump-sum form to agents and this redistribution improves insurance possibilities, we find that the optimal rate is sometimes positive. We also discuss the measurement of welfare gains or losses from inflation and their quantitative significance.

We show how to use security market data to restrict the admissible region for means and standard deviations of intertemporal marginal rates of substitution (IMRS’s) of consumers. Our approach is (i) nonparametric and applies to a rich class of models of dynamic economies; (ii) characterizes the duality between the mean-standard deviation frontier for IMRS’s and the familiar mean-standard deviation frontier for asset returns; and (iii) exploits the restriction that IMRS’s are positive random variables. The region provides a convenient summary of the sense in which asset market data are anomalous from the vantage point of intertemporal asset pricing theory.

The classical and early neoclassical economists knew that the essential function of money was its role as a medium of exchange. Recently, this idea has been formalized using search-theoretic noncooperative equilibrium models of the exchange process. The goal of this paper is to use a simple model of this class to analyze four substantive issues in monetary economics: the interaction between specialization and exchange, dual fiat currency regimes, the welfare improving role of money, and the susceptibility of monetary economies to extrinsic uncertainty.

A paradigm is presented where both the extent of financial intermediation and the rate of economic growth are endogenously determined. Financial intermediation promotes growth because it allows a higher rate of return to be earned on capital, and growth in turn provides the means to implement costly financial structures. Thus, financial intermediation and economic growth are inextricably linked in accord with the Goldsmith-McKinnon-Shaw view on economic development. The model also generates a development cycle reminiscent of the Kuznets hypothesis. In particular, in the transition from a primitive slow-growing economy to a developed fast-growing one, a nation passes through a stage where the distribution of wealth across the rich and poor widens.