Research Database

We study the general equilibrium effects of social insurance on the transition in a model in which the process of moving workers from matches in the state sector to new matches in the private sector takes time and involves uncertainty. As to be expected, adding social insurance to an economy without any improves welfare. Contrary to standard intuition, however, adding social insurance may slow transition. We show that this result depends crucially on general equilibrium interactions of interest rates and savings under alternative market structures.

We study models of credit with limited commitment, which implies endogenous borrowing constraints. We show that there are multiple stationary equilibria, as well as nonstationary equilibria, including some that display deterministic cyclic and chaotic dynamics. There are also stochastic (sunspot) equilibria, in which credit conditions change randomly over time, even though fundamentals are deterministic and stationary. We show this can occur when the terms of trade are determined by Walrasian pricing or by Nash bargaining. The results illustrate how it is possible to generate equilibria with credit cycles (crunches, freezes, crises) in theory, and as recently observed in actual economies.

We develop a model of the market for federal funds that explicitly accounts for its two distinctive features: banks have to search for a suitable counterparty, and once they meet, both parties negotiate the size of the loan and the repayment. The theory is used to answer a number of positive and normative questions: What are the determinants of the fed funds rate? How does the market reallocate funds? Is the market able to achieve an efficient reallocation of funds? We also use the model for theoretical and quantitative analyses of policy issues facing modern central banks.

A statistical definition of the natural unemployment rate hypothesis is advanced and tested. A particular illustrative structural macroeconomic model satisfying the definition is set forth and estimated. The model has "classical" policy implications, implying a number of neutrality propositions asserting the invariance of the conditional means of real variables with respect to the feedback rule for the money supply. The aim is to test how emphatically the data reject a model incorporating rather severe "classical" hypotheses.

This paper examines the quantitative importance of temporal aggregation bias in distorting parameter estimates and hypothesis tests. Our strategy is to consider two empirical examples in which temporal aggregation bias has the potential to account for results which are widely viewed as being anomalous from the perspective of particular economic models. Our first example investigates the possibility that temporal aggregation bias can lead to spurious Granger causality relationships. The quantitative importance of this possibility is examined in the context of Granger causal relations between the growth rates of money and various measures of aggregate output. Our second example investigates the possibility that temporal aggregation bias can account for the slow speeds of adjustment typically obtained with stock adjustment models. The quantitative importance of this possibility is examined in the context of a particular class of continuous and discrete time equilibrium models of inventories and sales. The different models are compared on the basis of the behavioral implications of the estimated values of the structural parameters which we obtain and their overall statistical performance. The empirical results from both examples provide support for the view that temporal aggregation bias can be quantitatively important in the sense of significantly distorting inference.

The paper surveys the recent literature on the fiscal implications of central bank balance sheets, with a special focus on political economy issues. It then presents the results of simulations that describe the effects of different scenarios for the Federal Reserve's longer-run balance sheet on its earnings remittances to the U.S. Treasury and, more broadly, on the government's overall fiscal position. We find that reducing longer-run reserve balances from $2.3 trillion (roughly the current amount) to $1 trillion reduces the likelihood of posting a quarterly net loss in the future from 30 percent to under 5 percent. Further reducing longer-run reserve balances from $1 trillion to pre-crisis levels has little effect on the likelihood of net losses.

This paper examines the seasonal pattern of accruals for loan-loss provisions and chargeoffs chosen by bank managers. Using the existing literature on intra-year discretionary accruals, knowledge of the incentive systems used to evaluate bank managers' performance, and various regulatory characteristics, we predict that accruals for provisions and chargeoffs will cluster in the fourth quarter of each year. We examine quarterly data for 105 large bank holding companies from the first quarter of 1980 through the fourth quarter of 1990. Our results indicate that: (1) provisions and chargeoffs are clustered in the fourth quarter, (2) this clustering is not related to the level of business activity of the banks, (3) the proximity of a bank's actual capital to its regulatory capital requirement does not affect this clustering, and (4) current provisions are affected both by current chargeoffs and by expectations about future chargeoffs. To examine whether the systematic characteristics of these loan-loss provision and chargeoff decisions are understood by users, we also estimate a quarterly equity valuation model in which quarterly provisions should be differentially weighted to reflect their seasonal characteristics. We find strong evidence to indicate that equity prices behave as if the market participants take these seasonal properties into account.

A random matching model with money is used to study the nominal yield on small denomination, bearer, safe, discount securities issued by the government. There is always one steady state with matured securities circulating at par and, for some parameters, another with them circulating at a discount. In the former, a necessary and sufficient condition for a positive nominal yield on not-yet-matured securities is exogenous discriminatory treatment of them by the government. In the latter, the post-maturity discount on securities induces a deeper pre-maturity discount even without such discriminatory treatment.

A model is constructed where banks provide access to a communication technology which facilitates trade. Bank liabilities may coexist with alternative means of payment in equilibrium, and there exist regions of the parameter space where banking dominates the payments system and where physical exchange media dominate. The model is consistent with some observations concerning the role of the banking system in economic development, and with characteristics of banking crises. In particular, in early stages of economic development: 1) rapid output growth is accompanied by an increasing share of banking in transactions activity and 2) there are recurrent banking "panics" where reductions in measured aggregate output coincide with increases in the use of alternative means of payment relative to bank liabilities. In later stages of development, growth slackens off, the share of banking in the payments system stabilizes and the economy is less likely to be subject to banking panics.

We describe a simple environment in which assets of varying qualities may be used for transactions and consumption. The quality of an asset is known to the seller but not the buyer. We show that this feature can generate a negative relationship between the transactions velocities of assets and their rates of return. We also discuss several versions of Gresham's Law which hold in this environment.

Economic equilibria are usually solutions to fixed point problems rather than solutions to convex optimization problems. This leads to two difficulties that are closely related: First, equilibria may be difficult to compute. Second, a model economy may have more than one equilibrium. This paper explores these issues for a number of stylized economies, including static economies that involve both pure exchange and production, economies that have infinite numbers of goods because of time and uncertainty, and economies with distortionary taxes and externalities. There are numerous numerical examples that illustrate the theory and could serve as test problems for algorithms.

This paper describes methods for conveniently formulating and estimating dynamic linear econometric models under the hypothesis of rational expectations. An econometrically convenient formula for the cross-equation rational expectations restrictions is derived. Models of error terms and the role of the concept of Granger causality in formulating rational expectations models are both discussed. Tests of hypothesis of strict econometric exogeneity along the lines of Sim’s are compared with a test that is related to Wu’s.

Theory typically does not give us reason to believe that economic models ought to be formulated at the same level of time aggregation at which data happen to be available. Nevertheless, this is frequently done when formulating econometric models, with potentially important specification-error implications. This suggests examining the alternatives, one of which is to model in continuous time. The primary difficulty in inferring the parameters of a continuous time model given sampled observations is the “aliasing identification problem.” This paper shows how the restrictions implied by rational expectations sometimes do, and sometimes do not, resolve the problem. This is accomplished very simply in the context of a hypothesis about the term structure of interest rates. The paper confirms and extends results obtained for another example by Hansen and Sargent.

How should a government use the power to commit to ensure a desirable equilibrium outcome? In this paper, I show a misleading aspect of what has become a standard approach to this question, and I propose an alternative. I show that the complete description of an optimal (indeed, of any) policy scheme requires outlining the consequences of paths that are often neglected. The specification of policy along those paths is crucial in determining which schemes implement a unique equilibrium and which ones leave room for multiple equilibria that depend on the expectations of the private sector.