We develop a theory of monotone comparative statics based on weak set order, or in short weak monotone comparative statics, and identify the enabling conditions in the context of individual choices, Pareto optimal choices for a coalition of agents, and Nash equilibria of games. Compared with the...

A contract with multiple agents may be susceptible to collusion. We show that agents' collusion imposes no cost in a large class of circumstances with risk neutral agents, including both uncorrelated and correlated types. In those circumstances, any payoff the principal can attain in the absence...

We develop a network-flow approach for characterizing interim-allocation rules that can be implemented by ex post allocations. Our method can be used to characterize feasible interim allocations in general multi-unit auctions where agents face capacity constraints, both ceilings and floors....

We study alternative methods of assigning scarce resources to individuals who may be liquidity-constrained. Selling the resources via auctions is increasingly popular, but that method may produce an inefficient allocation when agents are liquidity constrained. A simple non-market scheme such as...

This article studies different methods of assigning a good to budget-constrained agents. Schemes that assign the good randomly and allow resale may outperform the competitive market in terms of Utilitarian efficiency. The socially optimal mechanism involves random assignment at a discount--an...