Multi-objective (vector) combinatorial problem of finding the Pareto set with four kinds of non-linear partial criteria is considered. Necessary and sufficient conditions of that kind of stability of the problem (quasi-stability) are obtained. The problem is a discrete analogue of the lower semicontinuity by Hausdorff of the optimal mapping. Mathematics Subject Classification 2000: 90C10, 90C05...

We investigate whether having a unique equilibrium (or a given number of equilibria) is robust to perturbation of the payoffs, both for Nash equilibrium and correlated equilibrium. We show that the set of n-player finite normal form games with a unique correlated equilibrium is open, while this is not true of Nash equilibrium for n>2. The crucial lemma is that a unique correlated equilibrium is...

It is shown that (except for two well defined cases), the necessary and sufficient condition for any spherically symmetric distribution of fluid to leave the state of equilibrium (or quasi–equilibrium), is that the Weyl tensor changes with respect to its value in the state of equilibrium (or quasi–equilibrium). ∗Postal address: Apartado 80793, Caracas 1080A, Venezuela; E-mail address: laherrera...

We extend the analysis of [26] to handling more general utility functions: linear substitution functions, which include the Leontief utility. We show that the problem reduces to the general analytic center model discussed in [26]. Thus, the same complexity bound applies to approximating the Fisher equilibrium problem with linear substitution utilities. More importantly, we apply the model to sh...

In a game of common interest there is one action vector that all players prefer to every other. Yet there may be multiple Pareto-ranked Nash equilibria in the game and the ”coordination problem” refers to the fact that rational equilibrium play canot rule out Pareto-dominated equilibria. In this paper, I prove that two elements asynchronicity and a finite horizon are sufficient to uniquely sele...

We introduce a new class of equilibrium problems, known as mixed quasi invex equilibrium (or equilibrium-like) problems. This class of invex equilibrium problems includes equilibrium problems, variational inequalities, and variational-like inequalities as special cases. Several iterative schemes for solving invex equilibrium problems are suggested and analyzed using the auxiliary principle tech...

We consider a representative-agent equilibrium model where the consumer has quasi-geometric discounting and cannot commit to future actions. We restrict attention to a parametric class for preferences and technology and solve for time-consistent competitive equilibria globally and explicitly. We then characterize the welfare properties of competitive equilibria and compare them to that of a pla...