The paper studies equilibria for economies with imperfect competition and non-convex technologies. Following Negishi, firms maximise profits under downward-sloping perceived demand functions. Negishi's assumptions, in particular the assumption of a single monopolistic competitor in each market,...

Rational expectations do not require beliefs to be consistent with history and with what agents can conclude from it. Actually, at a rational expectations equilibrium agents may hold beliefs that explain poorly the history they observe, even when restricted to only those rationalizing their...

Extrinsic uncertainty is effective at a competitive equilibrium. This is generic if spot markets are inoperative: the only objects of exchange are assets for the contingent delivery of commodities; and the asset market is incomplete. The structure of payoffs of assets may allow for non-trivial...

Extrinsic uncertainty is effective at a competitive equilibrium. This is generic if spot markets are inoperative: the only objects of exchange are assets for the contingent delivery of commodities; and the asset market is incomplete. The structure of payoffs of assets may allow for non-trivial...

This paper attemps to identify, in a framework deliberately stripped of unnecessary technical- ities, some of the basic reasons why adaptive learning may or may not lead to stability and convergence to self-fulfilling expectations in large socioeconomic systems where no agent, or collection of...

In an economy with asymmetric information, Rational Expectations Equilibria (REE) need not become asymptotically incentive compatible, even if many independent replicas of the economy are merged together. We identify a sub-class of REE for which this is nevertheless the case. It consists of...

We provide a definition of the rational expectations core in an atomless economy with asset markets and show that allocations in the core can be decentralized by a system of asset and spot prices as rational expectations equilibria.

This paper attempts to identify, in a framework deliberately stripped of unnecessary technicalities, some of the basic reasons why adaptative learning may or may not lead to stability and convergence to self-fulfilling expectations in large socioeconomic systems where no agent, or collection of...

We propose a general model of monopolistic competition, which encompasses existing models while being flexible enough to take into account new demand and competition features. The basic tool we use to study the market outcome is the elasticity of substitution at a symmetric consumption pattern,...

Recent extensions of the standard Dixit-Stiglitz (1977) model, that go beyond the CES sub-utility assumption, while maintaining monopolistic competition, have mainly emphasized the role of iintrasectoral substitutability. We argue that introducing oligopolistic competition can be an alternative...