Research Database

In an overlapping generations model with borrowing and lending, uncertainty, and asymmetric information, fiat money may be essential to the existence of a competitive equilibrium. It may also serve to enhance the information of economic agents in a well-defined sense. In addition, the model presented provides suggestions about why the presence of valued fiat currency is essential to existence of equilibrium, even though in equilibrium perfect substitutes for money may exist.

A model of credit rationing based on asymmetrically informed borrowers and lenders is developed. In this context, sufficient conditions are derived for an appropriate government policy response to credit rationing to be a continuously open discount window. It is also demonstrated that such a policy can be deflationary, and that given a commitment to operate in this way, the monopoly issue of liabilities can Pareto dominate their competitive issuance.

For a wide class of dynamic models, Chamley (1986) has shown that the optimal capital income tax rate is zero in the long run. Lucas (1990) has argued that for the U.S. economy there is a significant welfare gain from switching to this policy. We show that for the Bewley (1986) class of models with heterogeneous agents and incomplete markets (due to uninsured idiosyncratic shocks), and borrowing constraints the optimal tax rate on capital income is positive even in the long run. Quantitative analysis of a parametric version of such a model suggests that one cannot dismiss the possibility that the observed tax rates on capital and labor income for the U.S. economy are fairly close to being (long run) optimal. We also provide an existence proof for the dynamic Ramsey optimal tax problem in this environment.

Micro data over the life cycle shows two different patterns of consumption of housing and non-housing goods: the consumption profile of non-housing goods is hump-shaped while the consumption profile for housing first increases monotonically and then flattens out. These patterns hold true at each consumption quartile. This paper develops a quantitative, dynamic general equilibrium model of life cycle behavior, which generates consumption profiles consistent with the observed data. Borrowing constraints are essential in explaining the accumulation of housing assets early in life, while transaction costs are crucial in generating the slow downsizing of the housing assets later in life. The bequest motives play a role in determining total life time wealth, but not the housing profile.

We propose a definition of time consistent policy for infinite horizon economies with competitive private agents. Allocations and policies are defined as functions of the history of past policies. A sustainable equilibrium is a sequence of history-contingent policies and allocations that satisfy certain sequential rationality conditions for the government and for private agents. We provide a complete characterization of the sustainable equilibrium outcomes for a variant of Fischer's (1980) model of capital taxation. We also relate our work to recent developments in the theory of repeated games.

This paper examines the extent to which the equity premium puzzle can be resolved by taking account of the fact that stockholders bear a disproportionate share of output uncertainty. We do this in the context of a non-Walrasian RBC model where risk reallocation is justified by borrowing restrictions. The risk shifting mechanism we propose has the same effect as would arise from a substantial increase in the risk aversion parameter of the representative agent. As with more standard RBC models, it remains that our model is unable to replicate key financial statistics. In particular, the observation that the equity return is more variable than national product cannot be accounted for under standard technology assumptions.