Alvin E. Roth won the Nobel in Economics for "the theory of stable allocations and the practice of market design". If you think that has no relevance to your daily life, you're absolutely wrong. (Especially if you live in the US.)
Roth's work deals with modeling real-life scenarios and finding logical solutions. He is most famous for his contribution to the National Resident Matching Program. The NRMP matches doctors to hospitals.
Doctors, as we know, vary in quality. So do hospitals. Also, many hospitals have specializations which apply to some doctors better than others. Basically, the NRMP optimizes the distribution, so that doctors are happy with the hospital, and vice versa. So, if you live in the US and saw a doctor (and, face it, you have), the NRMP played a hand in it.
Roth didn't create the NRMP itself, but he proved that it's stable, and also extended the algorithm to apply to married doctors. His other contributions involve matching children to schools, and kidney donors to recipients.
We hope that last one is not relevant to you, dear reader.