Emma Moreno-García

Blocking Efficacy of Small Coalitions in Myopic Economies

Abstract We consider a continuum economy with infinitely many commodities and show that, for any positive e, the core of the economy coincides with the set of allocations which are not blocked by any coalition with measure less than e. Actually, our main result is an extension of Grodals (1972, Econometrica40, 581–583) result and, therefore, Schmeidlers (1972, Econometrica40, 579–580) result to economies whose commodity space is l∞, for myopic preferences. Journal of Economic Literature Classification Numbers: C71, D51.

The Veto Mechanism Revisited

It is difficult to argue that coalition formation is costless and free. In this paper, only a subset of the set of all possible coalitions in an economy or a game, is considered to be really formed. The consequences that such restriction has on the veto mechanism are analyzed. The restricted veto mechanism is extended to the pondered veto mechanism with rates of participation of the the players. It is shown that it is enough to consider the veto power of a subsetSof coalitions, which differs from the set of all coalitions, in order to obtain the Walrasian allocations or, alternatively, the Edgeworth equilibria. In particular, it is shown that the pondered veto power, with rates of participation arbitrarily close to one, of only one coalition, namely, the coalition of all agents, blocks any non Walrasian allocation.

Real indeterminacy of equilibria and manipulability

Abstract In this paper, we analyze the indeterminacy of equilibria in financial markets and propose a selection mechanism. We suggest that there is one equilibrium that prevails over the others, as a result of the market power of the agents that some states of nature become monopolists of certain commodities. Given a financial assets model, we define a price game and show the existence of mixed strategies equilibria. Then we purify these equilibria by considering a price game with incomplete information.

Walrasian analysis via two-player games

We associate to any pure exchange economy a game with only two players, regardless of the number of consumers. In this two-player game, each player represents a different role of the society, formed by all the individuals in the economy. Player 1 selects feasible allocations trying to make Pareto improvements. Player 2 chooses an alternative from the wider range of allocations that are feasible in the sense of Aubin. The set of Nash equilibria of our game is non-empty and our main result provides a characterization of Walrasian equilibria allocations as strong Nash equilibria of the associated society game.

Linear exchange economies with a continuum of agents

Abstract. The purpose of this paper is to study how the equilibrium prices vary with respect to the initial endowments in a linear exchange economy with a continuum of agents. We first state the model and give conditions of an increasing strength for existence, uniqueness and continuity of equilibrium prices. Then, if we restrict ourselves to economies with essentially bounded initial endowments and if we assume that there is, from the point of view of preferences, only a finite number of types of agents, we show that, on an open dense subset of the space of initial endowments, the equilibrium price vector is an infinitely differentiable function of the initial endowments. The proof of this claim is based on a formula allowing to compute the equilibrium price vector around a so-called “regular” endowment where it is known.

On restricted bargaining sets

In this paper we analyze the behavior of bargaining sets in continuum economies when there are restrictions on the formation of coalitions. We provide several characterizations of Vind’s (J Math Econ 21:89–97, 1992) bargaining set in terms of its restricted versions, where not all the coalitions are formed. Moreover, we show that these equivalences do not hold for Mas-Colell’s (J Math Econ 18:129–139, 1989) bargaining set. These findings highlight the different nature of both notions of bargaining sets. Finally, we illustrate the impossibility of extrapolating our results to a more general setting.

Strategic Equilibria With Partially Consumable Withholdings

In this paper, we consider a pure exchange economy with a finite number of agents who behave strategically on endowments. A notion of strategic equilibrium with partial disposability is defined and it is shown the existence of mixed strategies equilibria. Purification results on the strategic equilibrium are obtained by considering a Walrasian endowment game with incomplete information. Finally, we obtain an asymptotic result by replicating the economy.

On neutrality with multiple private and public goods

We obtain an analogue of the neutrality result of Warr (1983) and Bergstrom et al. (1986) for economies with both multiple private and public goods.