Design of (international) kidney exchange: ex-post rejection versus ex-ante withholding

 Here's a paper by several Dutch computer scientists, which seems to be motivated by the problem of international kidney exchange within the EU, in which there are lots of concerns about fairness between countries.  But (as the paper notes) these could also apply to individual transplant centers, in the U.S. context.  The thrust of the paper is that looking for exchanges that won't be rejected ex post in a full information environment may be more productive than looking for ways to incentivize countries or transplant centers to reveal their full sets of patient donor pairs in an incomplete information environment.

Blom, Danny, Bart Smeulders, and Frits Spieksma. "Rejection-Proof Mechanisms for Multi-Agent Kidney Exchange." Games and Economic Behavior (2023).

Abstract: Kidney exchange programs (KEPs) increase kidney transplantation by facilitating the exchange of incompatible donors. Increasing the scale of KEPs leads to more opportunities for transplants. Collaboration between transplant organizations (agents) is thus desirable. As agents are primarily interested in providing transplants for their own patients, collaboration requires balancing individual and common objectives. In this paper, we consider ex-post strategic behavior, where agents can modify a proposed set of kidney exchanges. We introduce the class of rejection-proof mechanisms, which propose a set of exchanges such that agents have no incentive to reject them. We provide an exact mechanism and establish that the underlying optimization problem is 

we also describe computationally less demanding heuristic mechanisms. We show rejection-proofness can be achieved at a limited cost for typical instances. Furthermore, our experiments show that the proposed rejection-proof mechanisms also remove incentives for strategic behavior in the ex-ante setting, where agents withhold information.