Random mechanisms have been used in real-life situations for reasons such as fairness. Voting and matching are two examples of such situations. We investigate whether desirable properties of a random mechanism survive decomposition of the mechanism as a lottery over deterministic mechanisms that...

In a moneyless market, a non storable, non transferable homogeneous commodity is reallocated between agents with single-peaked preferences. Agents are either suppliers or demanders. Transfers between a supplier and a demander are feasible only if they are linked, and the links form an arbitrary...

A high court has to decide whether a law is constitutional, un- constitutional, or interpretable. The voting system is runoff. Runoff voting systems can be interpreted both, as social choice functions or as mechanisms. It is known that, for universal domains of preferences, runoff voting systems...

In a voting model where the set of feasible alternatives is a subset of a product set $A = A_1\times\cdots\ldots{}A_m$ of $m$ finite categories, we characterize the set of all strategy-proof social choice functions for three different types of preference domains over $A$, namely for the domains...

In this paper, we revisit a long-standing question on the structure of strategy-proof and Pareto-efficient social choice functions (SCFs) in classical exchange economies (Hurwicz (1972)). Using techniques developed by Myerson in the context of auction-design, we show that in a specific...

We consider the problem of allocating objects to a group of agents and how much agents should pay. Each agent receives at most one object and has non-quasi-linear preferences. Non-quasi-linear preferences describe environments where payments influence agents' abilities to utilize objects or...

A social choice function is group strategy-proof on a domain if no group of agents can manipulate its final outcome to their own benefit by declaring false preferences on that domain. Group strategy-proofness is a very attractive requirement of incentive compatibility. But in many cases it is...

We observe that three salient solutions to matching, division and house allocation problems are not only (partially) strategy-proof, but (partially) group strategy-proof as well, in appropriate domains of definition. That is the case for the Gale-Shapley mechanism, the uniform rule and the top...

We observe that many salient rules to allocate private goods are not only (partially) strategy-proof, but also (partially) group strategy-proof, in appropriate domains of definition. That is so for solutions to matching, division, cost sharing, house allocation and auctions, in spite of the...

This paper considers the problem of allocating N indivisible objects among N agents according to their preferences when transfers are not allowed, and studies the tradeoff between fairness and efficiency in the class of strategy-proof mechanisms. The main finding is that for strategy-proof...