Weakly Fair Allocations and Strategy-Proofness

This paper investigates the problem of allocating two types of indivisible objects among a group of agents when a priority-order must be respected and when only restricted monetary transfers are allowed. Since the existence of a fair allocation not generally is guaranteed due the the restrictions on the money transfers, the concept of fairness is weakened, and a new concept of fairness is introduced. This concept is called weak fairness. We define an allocation rule that implements weakly fair allocations and demonstrate that it is coalitionally strategy-proof. In fact, it is the only coalitionally strategy-proof allocation rule that implements a weakly fair allocation.