Efficiency and prices in economies of overlapping generations

In a general economy of overlapping generations, I introduce a notion of uniform ine±ciency, corresponding to the occurrence of a Pareto improvement with a small uniform destruction of resources (Debreu [11]). I provide necessary and su±cient conditions for uniform ine±ciency in terms of competitive equilibrium prices. Minimal assumptions are needed for such a complete characterization; moreover, proofs reduce to simple and short direct arguments. Finally, I verify that uniform ine±ciency is preserved under perturbations of the endowments, a property that has not been established for the canonical notion of ine±ciency. Remarkably, an allocation is unifoOverlapping generations; e±ciency; competitive prices; Cass Criterion; social security

A Characterization of Inefficiency in Stochastic Overlapping Generations Economies

In this paper, we provide a characterization of interim inefficiency in stochastic economies of overlapping generations under possibly sequentially incomplete markets. With respect to the established body of results in the literature, we remove the hypothesis of two-period horizons, by considering longer, though uniformly bounded, horizons for generations. The characterization exploits a suitably Modified Cass Criterion, grounded on the long-rung behavior of compounded safe interest rates and independent of the length of horizons of generations. Thus, the hypothesis of two-period horizons is purely heuristic in establishing a criterion for inefficiency. In addition, for sequentially incomplete markets, we adopt a suitable notion of unambiguous inefficiency, separating the inefficient intertemporal allocation of resources from incomplete risk-sharing. Unambiguous inefficiency reduces to inefficiency when markets are sequentially complete.

Asset Prices, Debt Constraints and Inefficiency

In this paper, we consider economies with (possibly endogenous) solvency constraints under uncertainty. Constrained ine±ciency corresponds to a feasible redistribution yielding a welfare improvement beginning from every contingency reached by the economy. A sort of Cass Criterion (Cass [10]) completely characterizes constrained inefficiency. This criterion involves only observable prices and requires low interest rates in the long-run, exactly as in economies with overlapping generations. In addition, when quantitative limits to liabilities arise from participation constraints, a feasible welfare improvement, subject to participation, coincides with the introduced notion of constrained inefficiency.In this paper, we consider economies with (possibly endogenous) solvency constraints under uncertainty. Constrained ine±ciency corresponds to a feasible redistribution yielding a welfare improvement beginning from every contingency reached by the economy. A sort of Cass Criterion (Cass [10]) completely characterizes constrained inefficiency. This criterion involves only observable prices and requires low interest rates in the long-run, exactly as in economies with overlapping generations. In addition, when quantitative limits to liabilities arise from participation constraints, a feasible welfare improvement, subject to participation, coincides with the introduced notion of constrained inefficiency.Non-Refereed Working Papers / of national relevance onl

Convex dynamic programming with (bounded) recursive utility

We consider convex dynamic programs with general (bounded) recursive utilities. The Contraction Mapping Theorem fails when the utility aggregator does not obey any discounting property. This failure occurs even with traditional aggregators and certainty equivalent specifications. However, the Bellman operator admits a unique fixed point when an interior policy is feasible. This happens because utility values are unique at interior consumption plans and, when an interior perturbation is feasible, drops in utility values can be avoided

Monetary Equilibria over an Infinite Horizon.

Money provides liquidity services through a cash-in-advance constraint. The exchange of commodities and assets extends over an infinite horizon under uncertainty and a sequentially complete asset market. Monetary policy sets the path of rates of interest and accommodates the demand for balances. A public authority, inheriting a strictly positive public debt, raises revenue from taxes and seignorage. Competitive equilibria exist, under mild solvency conditions. But, for a fixed path of rates of interest, there is a nontrivial multiplicity of equilibrium paths of prices of commodities. Determinacy requires that, subject to no-arbitrage and in addition to rates of interest, the prices of state-contingent revenues be somehow determined.money; equilibrium; indeterminacy; monetary policy; fiscal policy

An argument for positive nominal interest

In a dynamic economy, money provides liquidity as a medium of exchange. A central bank that sets the nominal rate of interest and distributes its profit to shareholders as dividends is traded in the asset market. A nominal rates of interest that tend to zero, but do not vanish, eliminate equilibrium allocations that do not converge to a Pareto optimal allocation. Key words: nominal rate of interest; dynamic efficiency. JEL classification numbers: D-60; E-10