Research Database

This paper essentially puts together procedures that are used in the computation of equilibria in models with a very large number of heterogeneous agents. It is not a complete description of all procedures used in the literature. It describes procedures that deal with infinitely lived agent versions of the growth model with and without aggregate uncertainty, overlapping generations models, and dynamic political economy models.

We ask what fraction of the variation in incomes across countries can be accounted for by investment distortions. In our neoclassical growth model the relative price of investment to consumption is a good measure of the distortions. Using data on relative prices we estimate a stochastic process for distortions and compare the resulting variance of incomes in the model to that in the data. We find that the variation of incomes in the model is roughly 4/5 of the variability of incomes in the data. Our model does well in accounting for 6 key regularities on income and investment in the data.

The paper itself is followed by three appendices: Appendix 1 describing the log-likelihood function, Appendix 2 describing the construction of labor share of income associated with the production of consumption and investment goods, and the Data Appendix.

This study uses data from the Panel Survey of Income Dynamics (PSID) to address a number of questions about life cycle earnings mobility. It develops a dynamic reduced form model of earnings and marital status that is nonstationary over the life cycle. The study reaches several firm conclusions about life cycle earnings mobility. Incorporating non-Gaussian shocks makes it possible to account for transitions between low and higher earnings states, a heretofore unresolved problem. The non-Gaussian distribution substantially increases the lifetime return to post-secondary education, and substantially reduces differences in lifetime wages attributable to race. In a given year, the majority of variance in earnings not accounted for by race, education and age is due to transitory shocks, but over a lifetime the majority is due to unobserved individual heterogeneity. Consequently, low earnings at early ages are strong predictors of low earnings later in life, even conditioning on observed individual characteristics.

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.

We study a random-matching, absence-of-double-coincidence environment in which people cannot precommit and in which there are two imperfect ways of keeping track of what other people have done in the past: money and a public record of all past actions that is updated with an average lag. We study how the magnitude of that lag affects the allocations that are optimal from among allocations that are stationary and feasible and that satisfy incentive constraints which arise from the absence of commitment and the imperfect ways of keeping track of what others have done in the past.

We consider a simple environment in which individuals receive income shocks that are unobservable to others and can privately store resources. We show that this ability to privately store can undercut the ability to shift resources across individuals to the extent that the efficient allocation only involves consumption smoothing over time, as opposed to insurance (consumption smoothing over states) if the rate of return on savings is not too far below the rate of time preference, or, alternatively, if the worst possible outcome is sufficiently dire. We also show that unlike environments without unobservable storage, the symmetric efficient allocation is decentralizable through a competitive asset market in which individuals trade risk-free bonds among themselves.

This study establishes several facts about medieval monetary debasements: they were followed by unusually large minting volumes and by increased seigniorage; old and new coins circulated concurrently; and, at least some of the time, coins were valued by weight. These facts constitute a puzzle because debasements provide no additional inducements to bring coins to the mint. On theoretical and empirical grounds, the authors reject explanations based on by-tale circulation, nominal contracts, and sluggish price adjustment. They conclude that debasements pose a challenge to monetary economics.

In the postwar period velocity has risen so sharply in the U.S. that the ratio of money to nominal output has fallen by a factor of three. We analyze the implications of shrinking money for the real effects of a monetary shock in two classes of equilibrium monetary business cycle models: limited participation (liquidity) models and predetermined (sticky) price models. We show that the liquidity model predicts that a rise in velocity leads to a substantial reduction in the real effects of a monetary shock. In sharp contrast, we show that the real effects of a monetary shock in the sticky price model are largely invariant to changes in velocity. We provide evidence that suggests that the real effects of monetary shocks have fallen over the postwar period.

We consider the problem of an insurer who enters into a repeated relationship with a set of risk averse agents in the presence of ex post verification costs. The insurer wishes to minimize the expected cost of providing these agents a certain expected utility level. We characterize the optimal contract between the insurer and the insured agents. We then apply the analysis to the provision of deposit insurance. Our results suggest—in a deposit insurance context—that it may be optimal to utilize the discount window early on, and to make deposit insurance payments only later, or not at all.

In U.S. elections, voters often vote for candidates from different parties for president and Congress. Voters also express dissatisfaction with the performance of Congress as a whole and satisfaction with their own representative. We develop a model of split-ticket voting in which government spending is financed by uniform taxes but the benefits from this spending are concentrated. While the model generates split-ticket voting, overall spending is too high only if the president’s powers are limited. Overall spending is too high in a parliamentary system, and our model can be used as the basis of an argument for term limits.