Ulric B. and Evelyn L. Bray Social Sciences Seminar

Wednesday, April 28, 2021
12:00pm to 1:00pm
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Online Event
Unpaired Kidney Exchange: Overcoming Double Coincidence of Wants without Money (with Julien Combe, Yinghua He, Victor Hiller, Robert Shimerk and Olivier Tercieux)
Mohammad Akbarpour, Associate Professor of Economics, Graduate School of Business, Stanford University,

Abstract: For an incompatible patient-donor pair, kidney exchanges often forbid receipt-before-donation (the patient receives a kidney before the donor donates) and donation-before-receipt, causing a double-coincidence-of-wants problem. Our proposal, the Unpaired kidney exchange algorithm, uses "memory" as a medium of exchange to eliminate these timing constraints. In a dynamic matching model, we prove that Unpaired delivers a waiting time of patients close to optimal and substantially shorter than currently utilized state-of-the-art algorithms. Using a rich administrative dataset from France, we show that Unpaired achieves a match rate of 57 percent and an average waiting time of 440 days. The (infeasible) optimal algorithm is only slightly better (58percent and 425 days); state-of-the-art algorithms deliver less than 34 percent and more than695 days. We draw similar conclusions from the simulations of two large U.S. platforms. Lastly, we propose a range of solutions that can address the potential practical concerns of Unpaired.

How to view the seminar:
Sign up for a free twitch.tv account, and tune in on Wednesdays at noon pacific time on twitch.tv/caltechecontheory. You will be able to ask questions on the twitch chat.

For more information, please contact Letty Diaz by email at letty.diaz@caltech.edu.