We consider the problem of fairly reallocating the individual endowments of a perfectly divisible good among agents with single-peaked preferences. We provide a new concept of fairness, called position-wise envy-freeness, that is compatible with individual rationality. This new concept requires...

We prove a general possibility result for collective decision problems where individual allocations are one-dimensional, preferences are single-peaked (strictly convex), and feasible allocation profiles cover a closed convex set. Special cases include the celebrated median voter theorem (Black...

We analyze bankruptcy problems with an indivisible object, where real owners and outside traders want to allocate an indivisible object among them with monetary compensation. The object might be a company that has gone bankrupt or a house left by a parent who has died, and so on. We show that...

We consider the allocation problem of assigning heterogenous objects to a group of agents and determining how much they should pay. Each agent receives at most one object. Agents have non-quasi-linear preferences over bundles, each consisting of an object and a payment. Especially, we focus on...

We study strategy-proof rules for choosing between two alternatives. We consider the full preference domain which allows for indifference. In this framework, for strategy proof rules, ontoness does not imply efficiency. We weaken the requirement of efficiency to ontoness and characterizes the...

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...

Condorcet domains are sets of linear orders with the property that, whenever the preferences of all voters of a society belong to this set, their majority relation has no cycles. We observe that, without loss of generality, every such domain can be assumed to be closed in the sense that it...

Call a mechanism that associates each profile of preferences over candidates to an ambiguous act an Ambiguous Social Function (ASCF). This paper studies the strategy-proofness of ASCFs. We find that an ASCF is unanimous and strategyproof if and only if there exists a nonempty subset of voters,...

We consider strategy-proof rules operating on a rich domain of preference profiles in a set up where multiple private goods have to be assigned to a set of agents with entitlements where preferences display satiation. We show that if the rule is in addition "desirable", in that it is tops-only,...