North America metropolitan area by population in North America: Greater Mexico City. Canada also breaks into the top ten largest metropolitan areas with the Toronto metropolitan area having six million people. The proximity of cities to each other on the Canada–United States border and Mexico–United States border has led to the rise of international metropolitan areas. These urban agglomerations are observed at their largest and most productive in Detroit–Windsor and San Diego–Tijuana and experience large commercial, economic, and cultural activity. The metropolitan areas are responsible for millions of dollars of trade dependent on international freight. In Detroit-Windsor the Border Transportation Partnership study
Demographics of New York City Indians, Dominicans, Chinese, Irish, Russian, and German. The Puerto Rican population of New York City is the largest outside Puerto Rico. The New York City metropolitan area is also home to the largest Italian population in North America and the third largest Italian population outside of Italy. Italians emigrated to the city in large numbers in the early 20th century, establishing several "Little Italies". The Irish also have a notable presence, along with Germans. New York City has a high degree of income variation. In 2005 the median household income in the highest census tract was reported to be $188,697,