The U.N.’s World Happiness Report — created to curtail our unhealthy obsession with G.D.P. — is dominated every year by the Nordic countries. We head to Denmark to learn the secrets of this happiness epidemic (and to see if we should steal them).

Games are as old as civilization itself, and some people think they have huge social value regardless of whether you win or lose. Tom Whipple is not one of those people. That’s why he consulted an army of preposterously overqualified experts to find the secret to winning any game.

You wouldn’t think you could win a Nobel Prize for showing that humans tend to make irrational decisions. But that’s what Richard Thaler has done. The founder of behavioral economics describes his unlikely route to success; his reputation for being lazy; and his efforts to fix the world — one nudge at a time.

Celebrity chef Alex Guarnaschelli joins us to co-host an evening of delicious fact-finding: where a trillion oysters went, whether a soda tax can work, and how beer helped build an empire. Washington Post columnist Alexandra Petri is our real-time fact-checker.

We learn how to be less impatient, how to tell fake news from real, and the simple trick that nurses used to make better predictions than doctors. Journalist Manoush Zomorodi co-hosts; our real-time fact-checker is the author and humorist A.J. Jacobs.

Our co-host is comedian Christian Finnegan, and we learn: the difference between danger and fear; the role of clouds in climate change; and why (and when) politicians are bad at math. Washington Post columnist Alexandra Petri is our real-time fact-checker.

Our co-host is Grit author Angela Duckworth, and we learn fascinating, Freakonomical facts from a parade of guests. For instance: what we all get wrong about Darwin; what an iPod has in common with the “hell ant”; and how a “memory athlete” memorizes a deck of cards. Mike Maughan is our real-time fact-checker.

In the early 20th century, Max Weber argued that Protestantism created wealth. Finally, there are data to prove if he was right. All it took were some missionary experiments in the Philippines and a clever map-matching trick that goes back to 16th-century Germany.

The quirky little grocery chain with California roots and German ownership has a lot to teach all of us about choice architecture, efficiency, frugality, collaboration, and team spirit.

Some people argue that sugar should be regulated, like alcohol and tobacco, on the grounds that it’s addictive and toxic. How much sense does that make? We hear from a regulatory advocate, an evidence-based skeptic, a former F.D.A. commissioner — and the organizers of Milktoberfest.