“There is no mystery about the causes of the new boom. The rich have done very well over the last decade, and some of them, including hedge fund managers like Steven A. Cohen, are spending large sums of their money on art. New billionaires in China, India and, above all, Russia, have also entered the market. The mysterious part of the current mania lies in figuring out what exactly makes a piece of art worth $30 million instead of, say, $1 million.”