Kidney exchange with immunosuppressants

We investigate the implications of introducing immunosuppressants to the kidney exchange problem. Immunosuppressants relax biological constraints between patients and donors, allowing patients to receive transplants from any donor. Given the limited availability, we propose how to assign immunosuppressants and how to match patients to donors to facilitate transplants. We ask whether there exist Pareto efficient solutions that satisfy additional requirements of monotonicity and maximal improvement. We propose modifications of the top-trading cycles solutions to achieve these requirements. To quantify the welfare improvement as per our proposal, we conduct counterfactual analyses using transplant data from South Korea. Our result suggests that the current use of immunosuppressants could have been reduced by 55 percent.