WASHINGTON — Richard H. Thaler, whose work has persuaded many economists to pay more attention to human behavior, and many governments to pay more attention to economics, was awarded the Nobel Memorial Prize in Economic Sciences on Monday.

Professor Thaler is the rare economist to win a measure of fame before winning the prize. He is an author of a best-selling book, “Nudge,” about helping people to make better decisions. He also appeared in the 2015 film “The Big Short,” delivering what is surely one of the most widely viewed tutorials in the history of economics, on the causes of the 2008 financial crisis.

The Nobel committee, announcing the award in Stockholm, said that it was honoring Professor Thaler for his pioneering work in establishing that people are predictably irrational — that they consistently behave in ways that defy economic theory. People will refuse to pay more for an umbrella during a rainstorm; they will use the savings from lower gas prices to buy premium gasoline; they will offer to buy a coffee mug for $3 and refuse to sell it for $6.

The committee credited Professor Thaler, who teaches at the University of Chicago Booth School of Business, for moving economics toward a more realistic understanding of human behavior, and for using the resulting insights to improve public policies, notably a sweeping shift toward the automatic enrollment of employees in retirement savings programs.