Why is a shark in a tank of formaldehyde, the brainchild of Damien Hirst, such a celebrated piece at New York's Metropolitan Museum of Art? Why is a pile of rocks, designed by Robert Smithson, one of the most important installations in the Art Institute of Chicago's Modern Wing? David Galenson, Professor of Economics and the College, is the author of a new book, Conceptual Revolutions in 20th Century Art, which he says answers one of the most vexing questions of contemporary culture: Why is much of contemporary art so bizarre, and seemingly lacking in the intrinsic appeal and stylistic coherence of previous eras? Galenson, an economic historian, isn't as well known as colleagues Steven Levitt (Freakonomics) or Richard Thaler (Nudge), but his work on art has been far from ignored. He's been the subject of feature stories in Wired, the New York Times, the Financial Times and the New Yorker, in which Malcolm Gladwell described at length "Galeson's idea that creativity can be divided into types."