Jonah Lehrer writes The Frontal Cortex blog. He is a contributing editor at Wired and has also written for The New Yorker, Seed, Nature, the New York Times and is a contributor to Radio Lab. He is the author of two books, Proust was a Neuroscientist, and, most recently, How We Decide. There are historical moments when financial markets basically look like Ponzi schemes, he says. Tulipmania was a good example. They work great, until they no longer work, and then they just collapse like a house of cards. So they work well for all the people who are selling tulips for 20 florins or 30 florins, but all of sudden, for whatever reason, when they reach 101, the market disappears. And you realise you’re paying insane amounts of money for a flower. And there’s always the moment, when you read these stories, where looking back on it, it seems so absurd.