2 From U.S. Win Nobel in Economics
15/10/2012 7 comentarios
Two Americans, Alvin Roth and Lloyd Shapley, were awarded the Nobel Memorial Prize in Economic Science on Monday for their work on market design and matching theory, which relate to how people and companies find and select one another in everything from marriage to school choice to jobs to organ donations. Their work primarily applies to markets that do not have prices, or at least have strict constraints on prices. The laureates’ breakthroughs involve figuring out how to properly assign people and things to stable matches when prices are not available to help buyers and sellers pair up. Mr. Roth, 60, has put these theories to practical use, in his work on a program that matches new doctors to hospitals and more recently for project matching kidney donors. Public school systems in New York, Boston, Chicago, Denver use an algorithm based on his work to help assign students to schools. A professor at Harvard, he recently accepted a new position at Stanford. “Al has spent the last 30 years trying to make economics more like an engineering discipline,” said Parag Pathak, an economics professor at M.I.T. who has worked on school-matching systems with Roth. “The idea is to try to diagnose why the resource allocation systems are not working and how they can be engineered to produce something better.” Shapley, 89, a mathematician long associated with game theory, is a professor emeritus at the University of California, Los Angeles. He made some of the earliest theoretical contributions to research on market design and matching, in 1950s and 1960s. In a paper with David Gale in 1962, Mr. Shapley explained how individuals could be paired together in a stable match even when they disagreed about what the qualities made the right match. Paper focused on designing an ideal, perfectly stable marriage market: having mates find one another in a fair way, so no one who is already married would want (and be able) to break off and pair up with someone else who is already married. In the 1980s, Mr. Roth applied this work to matches for medical residency programs and eventually school choice. He was interested in how to keep matches fair, how to keep sophisticated players from manipulating the system to their advantage. In older matching systems, a student would apply to his first-choice school, which was often popular. If student did not get in, then the application would be sent on to student’s second choice. But if that was also popular choice, then that school’s program would have already filled up by the time his application was even considered, and the process would repeat itself with his third-choice school and so on. Even if the students were qualified to get into one of their top schools, they could be shut out because they did not rank their preferences strategically. This created an incentive to try to game the system by listing a less popular school as their first choice because that way they would at least have a chance of getting in somewhere. Mr. Roth designed a system in which students had an incentive to tell truth about where they wanted to go. A centralized office could then assign them to a school best suited for them, based both on their own preferences and the preferences of schools they were applying to. The school systems he helped create use a “deferred acceptance algorithm,” which was developed by Mr. Shapley’s theoretical work (…..)