Another huge value-de stroying hurricane is about to slam America, destroying billions of dollars of value. Another Katrina? No, another Christmas. This voluntary December calamity is explained in a darkly amusing little book about the size of an iPhone. "Scroogenomics: Why You Shouldn't Buy Presents for the Holidays" comes from a distinguished publisher, Princeton University Press, and an eminent author, Joel Waldfogel of the University of Pennsylvania's Wharton business school. He says that the crux of Yuletide economics, which common sense suggests and research confirms, is: