(CNN) -- Alvin E. Roth of Harvard University and Lloyd Shapley of UCLA have been awarded the Nobel Prize in economics for their work in market design and matching theory, the Royal Swedish Academy of Sciences announced Monday. Roth and Shapley's work focuses on finding the most efficient way to match parties in a transaction, whether it be students to schools or organ donors to recipients, according to the academy. Shapley used game theory to study matching models, and Roth built on them to make real-world changes to existing markets, including school choice and organ transplants, the academy said. Elements of their work are built into software that guides kidney donations in the United States, as well as in school choice models in New York, Boston, New Orleans and other U.S. cities, Roth told reporters Monday.
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NEW: U.S. economists win prize for study of market design and matching theory
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NEW: Their work is used in education and organ transplants, among other things
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Economics was added as a category in 1969 by the Swedish central bank
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Two American professors also shared the 2011 Nobel Prize for economics
This year's prize for economics was selected from among hundreds of nominations, the @placeholder committee said.