Chicago is an international hub for finance, commerce, industry, technology, telecommunications, and transportation: O’Hare International Airport is the second busiest airport in the world when measured by aircraft traffic; the region also has the largest number of U.S. highways and rail road freight. In 2012, Chicago was listed as an alpha global city by the Globalization and World Cities Research Network, and ranked seventh in the world in the 2014 Global Cities Index. Chicago has the third largest gross metropolitan product in the United States—about $630.3 billion according to 2014-2016 estimates. The city has one of the world’s largest and most diversified economies with no single industry employing more than 14% of the workforce.
In 2015, Chicago had over 52 million international and domestic visitors. Chicago’s culture includes the visual arts, novels, film, theater, especially improvisational comedy, and music, particularly jazz, blues, soul, gospel and house music. It also has professional sports teams in each of the major professional leagues. Chicago has many nicknames, the best-known being the Windy City.