If you're one of the more than 100,000 people in the United States waiting for a kidney transplant, you might not realize that an economist is trying to get that kidney to you faster. And he wants to make sure it's the best possible kidney for you, so you'll have many healthy years ahead.
The economist in question, Alvin Roth, won a Nobel Prize in 2012 for his work in matching markets. Those are markets where price isn't a key factor. You can't buy a good job or a spot in college. And you can't buy a kidney, because that's illegal.