In the summer of 2003, the New York Times Magazine sent Stephen J. Dubner, an author and journalist, to write a profile of Steven D. Levitt, a heralded young economist at the University of Chicago. Dubner, who was researching a book about the psychology of money, had lately been interviewing many economists and found that they often spoke English as if it were a fourth or fifth language. Levitt, who had just won the John Bates Clark Medal (a sort of junior Nobel Prize for young economists), had lately been interviewed by many journalists and found that their thinking wasn’t very . . . robust, as an economist might say. But Levitt decided that Dubner wasn’t a complete idiot. And Dub- ner found that Levitt wasn’t a human slide rule. The writer was daz- zled by the inventiveness of the economist’s work and his knack for explaining it. Despite Levitt’s elite credentials (Harvard undergrad, a PhD from MIT, a stack of awards), he approached economics in a no- tably unorthodox way.