Nobel laureate Shapley’s perfect marriage theory

SWEDEN: A study on how a group of single people ought to choose their partners was one of the topics that gave US duo Lloyd Shapley and Alvin Roth this year's Nobel Economics Prize.

In the 1960s, Shapley, an economist and mathematician at Harvard, and his colleague David Gale, analysed how to best match supply and demand on an abstract level. The theory had a practical application.

“They used marriage as one of their illustrative examples. How should ten women and ten men be matched, while respecting their individual preferences?” the Royal Swedish Academy of Sciences wrote.

The solution couldn't be giving everyone in the group their preferred partner, since several men preferred the same woman, and vice versa. Instead they formed couples that were in everyone's best interest, thanks to a theory known as “deferred acceptance”.

AFP