People I (Mostly) Admire Freakonomics

Victoria Groce is one of the best trivia contestants on earth. She explains the structure of a good question, why she knits during competitions, and how to memorize 160,000 flashcards.

The author of "Sapiens" has a knack for finding the profound in the obvious. He tells Steve why money is fiction, traffic can be mind-blowing, and politicians have a right to say stupid things in private.

When she's not rescuing chickens from coyotes, Susan Athey uses economics to address real-world challenges — from online ad auctions to carbon capture technology.

Khan Academy founder Sal Khan returns to share his vision for a new way to learn — and the conversation inspires Steve to make a big announcement.

Astronomer Jill Tarter spent her career searching for extraterrestrial intelligence. She explains what civilizations from other planets could teach us about our own future.

Game theorist Barry Nalebuff explains how he used basic economics to build Honest Tea into a multimillion-dollar business, and shares his innovative approach to negotiation.