Kidney Exchange in Matching Markets
Source: https://qz.com/421547/nobel-prize-winner-alvin-roth-explains-the-hidden-economics-behind-tinder-marriage-and-college-admissions/
As discussed in the class, in a Matching Market, people would reveal their preferences among the choices being provided to them. However, they might not get their very first choices even the prices are affordable — it is a two-way choice system. In the article “The hidden economic rules behind Tinder, marriage, kidneys, and college admissions,” Matt Philips, the writer, did an interview with Alvin Roth about his new book Who Gets What—and Why. Roth is not only an Economics professor of Stanford but also a guru of Matching Market. In this article, even though he mentions the applications of Matching Market in multiple fields, I will mainly focus on the kidneys exchange part and explain why it is a perfect example of Matching Markets.
According to the article, Professor Roth helped developed the National Resident Matching Program, which has connected many compatible recipients to willing kidney donors. Theoretically, the kidney exchange example could form a bipartite graph with N kidney-recipients on the right side and N kidney-givers on the left-hand side. However, there would never be a perfect matching in this scenario. As Professor Roth points out, the ratio between people who need kidney-transplantations and donators are nearly 6:1, which means there is a high-demand for kidneys in the whole country. Also, a donator could be compatible with multiple patients, but only one final recipient will be able to receive the transplant surgery. Thus, with the fact that there will always be fewer nodes (donators) on the left-hand side, the kidney-exchange graph has lots of constricted sets. This fact also corresponds to the idea being mentioned at the beginning of this post—kidney-needers reveal their preferences (for example, their blood types). But even if they can afford the prices (in this case it would be that the patients’ bodies are healthy enough to endure such long and painful surgery), they might not be able to receive the kidneys they need.
In my opinion, the impossibility of forming a perfect matching in the kidney-exchange market also generates some other concerning issues. For example, since commercial trades in human organs are illegal in most of the countries, the demand for organs in black markets hugely increases. Thus, the significant need for organs would possibly result in expanding criminal activities like kidnappings and murders, especially of young people and teenagers.