We model happiness as a measurement tool used to rank alternative actions. Evolution favors a happiness function that measures the individual’s success in relative terms. The optimal function is based on a time-varying reference point—or performance benchmark—that is updated...

"As an economist and a public intellectual, Gary Becker was a giant. He won a Nobel Prize for his groundbreaking work in human capital, the John Bates Clark Medal as the best American economist under 40, and the Presidential Medal of Freedom for his contributions to public life and welfare. He...