Research Database

We provide a theoretical treatment of temporal aggregation in models that exhibit long-term endogenously-generated steady growth; hence generalizing our previous analysis (Econometrica 62, 1994, pp. 635–56). We introduce the property of steady-growth invariance—that the long-term growth of the continuous-time economy not be affected by the discretization—which imposes consistency restrictions on the joint formulation of preferences and stock accumulation of the discrete-time approximation. We establish, under mild conditions, these restrictions in the form of necessary and sufficient conditions on the discretization.

In a general equilibrium setting, we study versions of the proposal to pay interest on reserves at the market rate. We argue that the proposal makes the demand for total reserves indeterminate whether interest is paid on total reserves or on required reserves only. One consequence is that tax financing of the proposal gives rise to a continuum of equilibria, equilibria which differ in real returns and consumption allocations. Another consequence is that an attempt to finance the proposal through earnings on the central bank’s portfolio either gives rise to an equilibrium with a zero nominal interest rate or fails to give rise to an equilibrium.

We modify a standard SIR epidemiological model to allow for testing and asymptomatic agents. We explore cross country variation's ability to allow for identification of key parameters of the model: the fatality rate and the evolution over time of the normalized transmission rate. We first show that as long as tests are applied only to agents who exhibit symptoms, those parameters cannot be identified. We briefly discuss which additional information may allow for identification. Finally, we also describe conditions under which the normalized transmission rate can be computed with very high accuracy, and how cross country evidence can be used to evaluate the effect of lockdowns on evolution of the effective transmission rate over time.

In a finite-trader version of the Diamond-Dybvig (1983) model, the symmetric, ex-ante efficient allocation is implementable by a direct mechanism (i.e., each trader announces the type of his own ex-post preference) in which truthful revelation is the strictly dominant strategy for each trader. When the model is modified by formalizing the sequential-service constraint (cf. Wallace, 1988), the truth-telling equilibrium implements the symmetric, ex-ante efficient allocation with respect to iterated elimination of strictly dominated strategies.

Consider an economy in which various types of labor are used to produce consumption, but not all types of labor are useful for upgrading the stock of organization capital–that is, for replacing old projects with more productive new projects. When news induces consumers to want to save more, low-quality projects are destroyed across all sectors of the economy, even though the economy is set to increase its stock of new projects. Labor that can be used to create new projects becomes more expensive and labor that cannot becomes cheap. Average wages may not change at all, and the employment of workers who cannot invest in new projects will decline. If physical capital complements the inputs of these workers, investment in physical capital tends to move together with their employment. These results are derived analytically for a prototype economy that has the essential ingredients of empirically relevant equilibrium models of firm heterogeneity.

This paper puts forward a method of policy simulation with an existing macroeconometric model under the maintained assumption that individuals form their expectations rationally. This new simulation technique grows out of Lucas' criticism that standard econometric policy evaluation permits policy rules to change but doesn't allow expectations mechanisms to respond as economic theory predicts they will. This technique is applied to versions of the St. Louis Federal Reserve model and the FRB-MIT-Penn model to simulate the effects of different constant money growth policies. I shall briefly summarize the current practice of policy evaluation and the Lucas critique in the first section. The second section includes an explanation of the method I propose. The third section includes the two illustrative applications. In the conclusion, I cannot resist the temptation to offer some opinions about the use and usefulness of econometric models.

This paper is motivated by a variety of empirical observations on the comovements of currency velocity, inflation, and the relative size of the “credit services” sector. By the credit services sector we mean the part of banking and credit sector which provides alternative means of transactions to using currency as well as other services which help people economize on currency. We incorporate the credit services sector into a monetary growth model. Our model makes two specific and new contributions. The first is to show that direct quantitative evidence on the welfare cost of low inflation using measures of the relative size of an appropriately defined credit services sector for the U.S.—essentially the cost incurred by banks and credit unions in providing demand deposit and credit card services—is consistent with the welfare cost measured using an estimated money demand curve following the classic analysis of Bailey (1956) and the more recent analysis of Lucas (1993). Both of these measures amount to about 0.5 percent of GNP. The second contribution is in providing welfare cost of inflation estimates over a range of inflation rates which have some new features. We find that the total welfare cost of inflation remains bounded at about 5 percent of consumption.