Michael A. Rees
University of Toledo
Department of Urology
3000 Arlington Avenue
Mail Stop 1091
Toledo, OH 43614
Institutional Affiliation: University of Toledo Medical Center
NBER Working Papers and Publications
|February 2019||An Empirical Framework for Sequential Assignment: The Allocation of Deceased Donor Kidneys|
with Nikhil Agarwal, Itai Ashlagi, Paulo J. Somaini, Daniel C. Waldinger: w25607
An organ transplant can improve a patient’s life while also realizing substantial savings in healthcare expenditures. Like many other scarce public resources, organs from deceased donors are rationed to patients on a waitlist via a sequential offer mechanism. The theoretical trade-offs in designing these rationing systems are not well understood and depend on agent preferences. This paper establishes an empirical framework for analyzing waitlist systems and applies it to study the allocation of deceased donor kidneys. We model the decision to accept an organ or wait for a more preferable organ as an optimal stopping problem, and develop techniques to compute equilibria of counterfactual mechanisms. Our estimates show that while some types of kidneys are desirable for all patients, there is...
|July 2012||The Need for (long) Chains in Kidney Exchange|
with Itai Ashlagi, David Gamarnik, Alvin E. Roth: w18202
It has been previously shown that for sufficiently large pools of patient-donor pairs, (almost) efficient kidney exchange can be achieved by using at most 3-way cycles, i.e. by using cycles among no more than 3 patient-donor pairs. However, as kidney exchange has grown in practice, cycles among n>3 pairs have proved useful, and long chains initiated by non-directed, altruistic donors have proven to be very effective. We explore why this is the case, both empirically and theoretically.
We provide an analytical model of exchange when there are many highly sensitized patients, and show that large cycles of exchange or long chains can significantly increase efficiency when the opportunities for exchange are sparse. As very large cycles of exchange cannot be used in practice, long non-simult...