[Related to the Economics in Practice on p. 217] Each year in New Orleans, Carnival season begins on January 6 and culminates with the city's biggest celebration of the year, Mardi Gras. This wildly popular celebration attracts people from around the world, and the city of New Orleans estimates that over half a million visitors attended the festivities in 2010. The Tuesday on which Mardi Gras falls each year has been declared a state holiday in Louisiana, with banks, post offices, and many private businesses closing for the day. On the basis of labor, explain why you think Mardi Gras has been declared a state holiday in Louisiana and why so many businesses in New Orleans are closed on that day.