Knowledge that Transforms

The paper deals with infinite horizon optimization problems. The existence of optimal solutions is obtained as a consequence of an asymptotic growth condition. We also exhibit finite horizon approximates that yield upper and lower bounds for the optimal values and whose optimal solutions converge to the long-term optimal trajectories.

This paper provides two results that are useful in proving the exist ence of and characterizing separating equilibria in signaling games. A key element in the analysis of separating equilibria is the examina tion of the implied incentive compatibility constraints. It is shown that these constraints imply differentiability of strategies. In addi tion, a monotonicity condition (which is similar to the single crossi ng condition) is analyzed that is necessary and sufficient for there to be a strategy satisfying the incentive compatibility constraints. As a direct consequence of these two results, the analysis of Paul Milgrom and John Roberts (1982) is considerably strengthened. Copyright 1987 by The Econometric Society.

A collective choice problem involves a set of agents and a set of feasi ble utility vectors. Many solutions to the collective choice problem (e.g., the Nash solution) are collectively rational, i.e., consistent with the maximization of some ordering of utility space. In this pap er, a stability condition due to J. C. Harsanyi is used to obtain the following integrability result: any solution satisfying Pareto optim ality, continuity, and bilateral stability can be represented by an a dditively separable Bergson-Samuelson social welfare function. Copyright 1987 by The Econometric Society.

This paper formulates a simple, regenerative, optimal-stopping model of bus-eng ine replacement to describe the behavior of Harold Zurcher, superinte ndent of maintenance at the Madison (Wisconsin) Metropolitan Bus Comp any. Admittedly, few people are likely to take particular interest in Harold Zurcher and bus engine replacement per se. The author focuses on a specific individual and capital good because it provides a simp le, concrete framework to illustrate two ideas: (1) a "bottom-up" a pproach for modeling replacement investment and (2) a "nested fixed point" algorithm for estimating dynamic programming models of discre te choice. Copyright 1987 by The Econometric Society.

Cet article donne des conditions suffisantes pour que la matrice Jacobienne de la demande concurrentielle agrge soit dfinie ngative.Cette proprit forte implique en particulier que l'axiome faible de la prfrence rvle est satisfait par la demande agrge, et que la demande totale pour chaque bien augmente lorsque son prix dc1'0 i t.Ces cond i tians suffisantes portent sur la distribution des prfrences et sont indpendantes de la distribution des revenus.L'approche repose sur la.notion de transformation homothtique d'une relatiof\de prfrence.On discute galement la porte pour ce type de problme de la notion de transformation affine d'une prfrence, qui introduit une structure algbrique intressante sur l'espace des prfrences.On montre galement comment le rsultat est li celui obenu par W. Hildenbrand (Econometrica (1983)) en posant des restrictions sur la distribution des revenus.

On propose une methode analytique simplifiee qui autorise le calcul, meme pour des systemes de dimension moyenne

This paper studies pure exchange economies with infinite dimensional commodity spacces in the setting of Riesz dual systems. An Edgeworth equilibrium is an allocation that belongs to the core of every replication of the ec onomy. Under some mild conditions, it is shown that (1) Edgeworth equ ilibria exist, (2) an allocation is an Edgeworth equilibrium if and o nly if it is an approximate quasiequilibrium, and (3) if preferences are uniformly proper, then every Edgeworth equilibrium is a quasiequi librium. The obtained results specialize to most exchange economies t hat have appeared in the literature of general equilib rium theory. Copyright 1987 by The Econometric Society.

The authors study duopolistic competition in a homogeneous good through time under the assumption that its current desirability is an exponentially-weighted function of accumulated past consumption. This implies that the current price of the good does not decline by as much to accommodate any given level of current consumption. Our an alysis is conducted in terms of a differential game. It is found that the equilibrium price corresponding to the open-loop Nash equilibriu m strategies approaches the static Cournot equilibrium price while th e equilibrium price corresponding to the closed-loop Nash equilibrium strategies, which are subgame perfect, approaches a price below it. Copyright 1987 by The Econometric Society.

The existence of competitive equilibrium is established for economies with a produc tion sector and an infinite dimensional space of commodities. The cru cial assumptions which are required (beyond those required in the fin ite dimensional setting) are bounds on marginal rates of substitution and marginal rates of transformation. Copyright 1987 by The Econometric Society.