We study mechanisms for environments in which only some of the agents are directly connected to a mechanism designer and the other agents can participate in a mechanism only through the connected agents' referrals. In such environments, the mechanism designer and agents may have different...

We study mechanisms for environments in which only some of the agents are directly connected to a mechanism designer and the other agents can participate in a mechanism only through the connected agents' referrals. In such environments, the mechanism designer and agents may have different...

This paper considers mechanism design problems in environments with ambiguity-sensitive individuals. The novel idea of the paper is to introduce ambiguity in mechanisms so as to exploit the ambiguity sensitivity of individuals. We prove a revelation principle for the partial implementation of...

In this paper we deal with situations of collective contests between two groups over a private prize. A well known way to divide the prize within the winning group is the prize sharing rule introduced by Nitzan, 1991. Since its introduction it has become a standard in the collective contests...

In the standard auction model, we provide a necessary and sufficient condition on the value domain under which non-trivial mechanisms exist that satisfy group strategy-proofness and symmetry. In particular, this condition is satisfied (violated) if values are drawn from a finite set (an interval)

Consider the problem of allocating k identical, indivisible objects among n agents, where k is less than n. The planner's objective is to give the objects to the top k valuation agents at zero costs to the planner and the agents. Each agent knows the identity of those k agents, as well as her...

The planner wants to give k identical, indivisible objects to the top k valuation agents at zero costs. Each agent knows her own valuation of the object and whether it is among the top k. Modify the (k 1)st-price sealed-bid auction by introducing a small participation fee and the option not to...

For division problems with single-peaked preferences, we show that all sequential allotment rules, a large subfamily of strategy-proof and efficient rules, are also obviously strategy-proof. Although obvious strategy-proofness is, in general, more restrictive than strategy-proofness, this is not...