Brief announcement: New mechanisms for pairwise kidney exchange

Abstract

In this paper, we consider the pairwise kidney exchange game. Ashlagi et al. [1] present a 2-approximation randomized truthful mechanism for this problem. We note that the variance of the utility of an agent in this mechanism may be as large as Ω(n2), which is not desirable in a real application. Here, we resolve this issue by providing a 2-approximation randomized truthful mechanism in which the variance of the utility of each agent is at most 2 + ε. Later, we derandomize our mechanism and provide a deterministic mechanism such that, if an agent deviates from the mechanism, she does not gain more than 2[log2 m].