How did a Damien Hirst shark ever come to be "worth" $12m, or a Jackson Pollock drip painting $140m? This enthralling, revelation-rich trip through the "money game" of the art market brings an economist's eye and a dry, sceptical wit to its absurdities. The secret, for Thompson, lies in the alchemy of modern branding for artists like Hirst, collectors like Saatchi, auctioneers like Sotheby's, galleries like Gagosian. The jaw drops and the head spins as this figure-packed expos shows, from Bacon to Warhol and Koons, how celebrity and marketing mated to breed hyper-inflation of prices and names. And it proves (with statistics) why art is a lousy investment.