Michael A. Rees

University of Toledo
Department of Urology
3000 Arlington Avenue
Mail Stop 1091
Toledo, OH 43614

E-Mail: EmailAddress: hidden: you can email any NBER-related person as first underscore last at nber dot org
Institutional Affiliation: University of Toledo Medical Center

NBER Working Papers and Publications

February 2019Equilibrium Allocations under Alternative Waitlist Designs: Evidence from Deceased Donor Kidneys
with Nikhil Agarwal, Itai Ashlagi, Paulo J. Somaini, Daniel C. Waldinger: w25607
Waitlists are often used to ration scarce resources, but the trade-offs in designing these mechanisms depend on agents preferences. We study equilibrium allocations under alternative designs for the deceased donor kidney waitlist. We model the decision to accept an organ or wait for a preferable one as an optimal stopping problem and estimate preferences using administrative data from the New York City area. Our estimates show that while some kidney types are desirable for all patients, there is substantial match-specific heterogeneity in values. We then develop methods to evaluate alternative mechanisms, comparing their effects on patient welfare to an equivalent change in donor supply. Past reforms to the kidney waitlist primarily resulted in redistribution, with similar welfare and orga...
July 2012The 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...
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