I prove that, in models with complementarities, some non-monotone comparative statics must select unstable equilibria; and, under additional regularity conditions, that monotone comparative statics selects stable equilibria. JEL Classification. C61, C62, C72, C73. Discussions with my advisers, Ilya Segal and Chris Shannon, were very important for this work. I am very grateful for their help. I ...

In this paper, we consider political competition games of two parties in multi-dimensional policy spaces, where the two parties have two factions, opportunists and militants, that intra-party bargain with each other. In such a game, we adopt the party-unanimity Nash equilibrium (PUNE) [Roemer (1998; 1999; 2001)] as an appropriate solution concept, and examine the general existence problem of th...

This paper studies equilibria of second price auctions when values and participation costs are both privation information and are drawn from general distribution functions. We consider the existence and uniqueness of equilibrium. It is shown that there always exists an equilibrium for this general economy, and further there exists a unique symmetric equilibrium when all bidders are ex ante homo...

We prove the existence of general equilibrium for continuous-time overlappinggenerations models. Previous theorems exclude all non-linear C.E.S. and von Neumann Morgenstern preferences and exclude production. Our primitive assumptions are satisfied by such preferences and by all Markovian production technologies satisfying Bewley's assumptions for Arrow Debreu models provided that storage is po...

Stable networks of order  where  is a natural number refer to those networks that are immune to coalitional deviation of size  or less. In this paper, we introduce stability of a finite order and examine its relation with efficient networks under anonymous and component additive value functions and the component-wise egalitarian allocation rule. In particular, we examine shapes of networks o...

An environment is studied in which mechanisms suggest public goods allocations and individuals then choose whether or not to submit their requested transfer to the central planner. The set of allocations such that unanimous participation is an equilibrium is shown to be sub-optimal in a wide variety of environments and shrinks to the endowment as the economy is replicated. Optimal public goods ...

This paper extends the formulation of complementarity in Milgrom and Shannon (1994) to the case of incomplete but acyclic preferences. It is shown that the problem can be reformulated as one with complete but intransitive preferences. In this case, quasi-supermodularity and single-crossing on their own do not guarantee either monotone comparative statics or equilibrium existence in pure strateg...

In this paper, we establish a convergence result for equilibria in systems of social interactions with many locally and globally interacting players. Assuming spacial homogeneity and that interactions between different agents are not too strong, we show that equilibria of systems with finitely many players converge to the unique equilibrium of a benchmark system with infinitely many agents. We ...

This paper analayzes different FTAA (Free Trade Area of the Americas) elements and the related economic, political, technological and social effects. We will demonstrate that, in Latin America, noncooperative or competitive equilibria do not solve the conflicts between FFTA supporters (the government and exporters) and detractors (social, religious and academic movements.) Finally, we will show...

This paper analyzes a stochastic best reply evolutionary model with inertia in normal form games. The long-run behavior of individuals in this model is investigated in the limit where experimentation rates tend to zero, while the expected number of experimenters, and hence also population sizes, tend to infinity. Conditions on the learning-rate which are necessary and sufficient for the evoluti...