Mainstream macro-models have assumed away financial frictions, in particular default. The minimum addition in order to introduce financial intermediaries, money and liquidity into such models is the possibility of default. This, in turn, requires that institutions and price formation mechanisms...

The concept of 'the core' originates in cooperative game theory and its introduction to economics in the 1960s as a basis for proofs of existence of general equilibrium is one of the earliest attempts to use game theory to address big questions in economics. Discovery of the core was met with...

The eductive approach consists of finding solutions consistent with common knowledge of individual rationality and the model. An equilibrium is stable whenever it is the unique outcome consistent with these assumptions. This is a strong stability criterion as it relies on no assumption of prior...

The paper introduces the assumption of costly information acquisition to the theory of mechanism design for matching allocation problems. It is shown that the assumption of endogenous information acquisition greatly changes some of the cherished results in that theory: in particular, the...

The paper examines the behaviour of ?evolutionary? models with epsilon-noise like those which have been used recently to discuss the evolution of social conventions. The paper is built around two main observations: that the?long run stochastic stability? of a convention is related to the speed...

An economy with a finite number of agents and a finite number of states is considered. An exogenous institutional rule prescribes what moves from one state to another are feasible to each coalition. At each time an agent is called to act with some exogenous probability, and he chooses a...

Multiplicity of equilibria is a common problem in many economic models. In general, it is impossible to devise methods that always find all equilibria for any type of model. A notable exception are models in which all equilibria are solutions to a system of polynomial equations since there are...

We study two-sided many-to-one matching markets with transferable utilities, e.g., labor and rental housing markets, in which money can exchange hands between agents, subject to distributional constraints on the set of feasible allocations. In such markets, we establish the efficiency of...

The goal of this paper is to establish a general fixed point theorem for upper semicontinuous set-values mappings in p-vector spaces ( p in (0, 1]), which include topological vector spaces as a special class. These new results provide an answer to Schauder conjecture in the affirmative under the...

Equilibrium assumptions posit relations between different people's beliefs and behavior without describing a process that causes these relations to hold. I show that because equilibrium models do not describe a causal process whereby one endogenous variable affects another, attempts to decompose...