A competitive market mechanism is a prominent example of a nonbinary social choice rule, typically defined for a special class of economic environments in which each social state is an economic allocation of private goods, and individuals’ preferences concern only their own personal...

We address some open issues regarding the characterization of double auctions. Our model is a two-sided commodity market with either finitely or infinitely many traders. We first unify existing formulations for both finite and infinite markets and generalize the characterization of market...

In general screening problems, implementable allocation rules correspond exactly to Walrasian equilibria of an economy in which types are consumers with quasilinear utility and unit demand. Due to the welfare theorems, an allocation rule is implementable if and only if it induces an efficient...

This paper studies the problem of random assignment with fractional endowments. Fractional endowments complicate matters because the assignment has to make an agent weakly better off than his endowment. I first formulate an exchange economy that resembles the random assignment problem and prove...

We address some open issues regarding the characterization of double auctions. Our model is a two-sided commodity market with either finitely or infinitely many traders. We first unify existing formulations for both finite and infinite markets and generalize the characterization of market...

Socialism is conceptualized as a society in which individuals cooperate, distinguished from capitalism, characterized as involving ubiquitous economic competition. Here, I embed a formal model of cooperation in an Arrow-Debreu model, using the Kantian optimization protocol, and define a...