What happens when a donor kidney becomes available to somebody who needs one? In the U.S., a hundred thousand people are waiting on lists, all with different ages, complications, and circumstances. How do you decide who gets it? In his new book, Voices in the Code, David Robinson ’04, a scholar and co-founder of the equity-focused NGO Upturn, takes a look at the algorithm used to match kidneys and patients, and on the latest PAWcast he discusses how it was developed. Algorithms are increasingly used for all kinds of decisions in public life, he says, making close examination of the ethics and morality within them ever more crucial.