Miami is a major center, and a leader in finance, commerce, culture, media, entertainment, the arts, and international trade. In 2012, Miami was classified as an "Alpha−" level world city in the World Cities Study Group's inventory. In 2010, Miami ranked seventh in the United States and 33rd among global cities in terms of business activity, human capital, information exchange, cultural experience, and political engagement. In 2008, Forbes magazine ranked Miami "America's Cleanest City", for its year-round good air quality, vast green spaces, clean drinking water, clean streets, and citywide recycling programs. According to a 2009 UBS study of 73 world cities, Miami was ranked as the richest city in the United States, and the world's seventh-richest city in terms of purchasing power. Miami is nicknamed the "Capital of Latin America" and is the largest city with a Cuban-American plurality.