Research Database

We develop an equilibrium concept in the Debreu (1954) theory of value tradition for a class of adverse selection economies which includes the Spence (1973) signaling and Rothschild-Stiglitz (1976) insurance environments. The equilibrium exists and is optimal. Further, all equilibria have the same individual type utility vector. The economies are large with a finite number of types that maximize expected utility on an underlying commodity space. An implication of the analysis is that the invisible hand works for this class of adverse selection economies.

Two policies toward payments-system risk are common, but superficially appear to be contradictory. One policy is to restrict the exposure to risk generated by one participant to other participants who are, by one measure or another, directly concerned with the risky participant. The other policy is to provide a “safety net,” typically provided by government and funded by taxes collected from all participants and even from non-participants, to share losses due to “systemic risk.” In this paper, we provide a model in which both of these policies can be constituents of an economically efficient regime of payments-risk management.

We consider the nature of optimal cyclical monetary policy in three different stochastic models with various shocks. The first is a pure liquidity effect model, the second is a cost of changing prices model, and the third is an optimal seinorage model. In each case we solve for the optimal monetary policy and describe how money growth and interest rates respond to shocks under the optimal policy. The shocks we consider are money demand shocks, productivity shocks, and government consumption shocks. All of the models have the feature that the Friedman rule of setting the nominal interest rate to zero is not optimal. Optimal policies are always time inconsistent even though lump sum taxation is allowed. At least in some instances we find that optimal policy dictates responses of money growth and interest rates which run counter to conventional wisdom.

In this paper, we generalize the notion of Pareto-efficiency to make it applicable to environments with endogenous populations. Two efficiency concepts are proposed, P-efficiency and A-efficiency. The two concepts differ in how they treat people who are not born. We show how these concepts relate to the notion of Pareto-efficiency when fertility is exogenous. We then prove versions of the first welfare theorem assuming that decision making is efficient within the dynasty. Finally, we give two sets of sufficient conditions for noncooperative equilibria of family decision problems to be efficient. These include the Barro and Becker model as a special case.

A model is presented in which governments can select real expenditure levels which are feasible, hut are sufficiently high that a balanced budget is impossible. Thus governments with large expenditures are committed to inflationary finance schemes. This is the case even though the governments in question have access to lump-sum taxes. In addition, the model can explain why poorer countries tend to make heavier use of the inflation tax than do wealthier countries, and can account for the existence of country-specific fiat monies.

The neoclassical growth model studied in Kydland and Prescott [1982] is modified to permit the capital utilization rate to vary. The effect of this modification is to increase the amplitude of the aggregate fluctuations predicted by theory as the equilibrium response to technological shocks. If following Solow [1957], the changes in output not accounted for by changes in the labor and tangible capital inputs are interpreted as being the technology shocks, the statistical properties of the fluctuations in the post-war United States economy are close in magintude and nature to those predicted by theory.