Gift giving can be wasteful. "We only spend $10 on ourselves if we find something that we expect is worth more than $10 to us," said Joel Waldfogel, an economist and the author of a study called "The Deadweight loss of Christmas.""But gift giving is different, because we're not buying for ourselves," he explained. "So we can spend $10 on something that's worth less than $10 to the recipient. It could be worth nothing to them.