Mardi Gras, with its masquerade balls, beads, and floats is a financial fest for New Orleans. One million people will jam the city's streets during the two weeks leading up to Fat Tuesday (Feb. 21), says Jennifer Day at the New Orleans Convention & Visitors Bureau. In 2011, those visitors had a $300 million economic impact on the city, accounting for 1.5 percent of New Orleans' gross domestic product, according to a study of Mardi Gras prepared by Toni Weiss, an economics professor at Tulane University.