Altruistic kidney donors help many, in Science News

Rachel Ehrenberg in Science News reports on long kidney chains: Altruistic kidney donors help many.

"Many people needing kidney transplants have a willing donor, but they can’t take the kidney because it’s not compatible with their blood type or immune system. Paired exchanges, where incompatible donor/recipient pairs swap kidneys with another incompatible pair, is one trick for getting kidneys into hard-to-match patients. Another trick is a donor chain: A person gives a kidney to a clearinghouse or kidney exchange, which can set off a chain of donations.

"Within the kidney transplant community, there’s been an ongoing debate over whether long chains ultimately mean more transplants. “The mathematical question was, are we really transplanting more people?” says Alvin Roth, an expert in game theory and market design at Harvard. “The answer is yes, a lot more.”
...
"It turns out to not be an easy problem. It’s very hard computationally,” says MIT’s Itai Ashlagi, who conducted the analysis along with Roth, MIT’s David Gamarnik, and Michael Rees, a transplant surgeon at the University of Toledo and medical director of the Alliance for Paired Donation, which arranged the first non-simultaneous chain of 10 kidney transplants."

The story also quotes a dissenting voice from Dorry Segev at Johns Hopkins...
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Here's the paper:
Ashlagi, Itai, David Gamarnik, Michael A. Rees and Alvin E. Roth, "The Need for (long) Chains in Kidney Exchange," working paper, May 2012.