Nobel laureate and New York Times columnist Paul Krugman has been known to say some wacky things. After the 9/11 attacks, he opined that they "could even do some economic good." In 2002 he wrote that only a housing bubble could rescue the U.S. economy. After the tsunami, Krugman argued that the Japanese nuclear disaster "could end up being expansionary." And just last month, Krugman went on CNN to claim that a fake alien invasion could pull the world out of recession in 18 months.