Furthermore, Kahneman says laziness is Thaler's "single best quality," Thaler writes in the preface of his 2015 book " Misbehaving ."

Yet his best friend Daniel Kahneman, who has also won the Nobel Prize in economics, calls him lazy.

U.S. economist Richard Thaler has an impressive resume. The "father of behavioral economics" received his master's in 1970 and Ph.D. in 1974, co-authored the global best seller " Nudge " as well as other books. Of yes, he won the 2017 Nobel Prize in economics .

In 2001, author Roger Lowenstein was writing an article for the New York Times Magazine about Thaler's work and "naturally wanted to talk to my old friend Danny," Thaler recalls.

Since Thaler happened to be visiting Kahneman at his home the day Lowenstein called, he agreed to stay and listen in on the phone interview. What he heard surprised him:

Hearing a friend tell an old story about you is not an exciting activity, and hearing someone praise you is always awkward. I picked up something to read and my attention drifted — until I heard Danny say: 'Oh, the best thing about Thaler, what really makes him special, is that he is lazy.' What? Really? I would never deny being lazy, but did Danny think that my laziness was my single best quality? I started waving my hands and shaking my head madly but Danny continued, extolling the virtues of my sloth.

To this day, Kahneman insists that it was a compliment, and that Thaler's laziness has been a huge asset to him professionally.

"My laziness, he claims, means I only work on questions that are intriguing enough to overcome this default tendency of avoiding work," Thaler writes.

To some degree, the economist agrees with his friend's claim. As Thaler explained on NPR's podcast "Hidden Brain": "He [Kahneman] says it means I'm only willing to work on things that are important. The truth is I'm only willing to work on things that are fun."

Focusing exclusively on ideas he finds exciting has paid dividends for his research and his career: He has managed to make economics appealing to others, too, and in so doing he changed, and popularized, his field.

After Thaler won the Nobel, Lowenstein wrote about Thaler again, this time for The Washington Post, saying, "If the only criteria for winning was making the dismal science un-dismal — even fun — Thaler would have won years ago. But because his work, to use an overused phrase that here fits, also revolutionized our understanding, Stockholm, finally, could not look the other way."

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