If the New York metropolitan area became a country tomorrow, it would have the 13th-biggest economy in the world, landing just below Australia and ahead of Spain.

That’s according to this new map created by Zara Matheson of the University of Toronto’s Martin Prosperity Institute. She looked at the projected 2014 gross output of some of the biggest metropolitan areas in the United States (according to this list assembled for the U.S. Conference of Mayors) and compared that with the national gross domestic products for the biggest economies in the world (circa 2012, the most recent year for which data was available).

Economic activity in this country is narrowly concentrated in a handful of major cities. This map helps show just how big these cities are when compared with some of the world’s biggest economies:

(Courtesy of Zara Matheson/Martin Prosperity Institute)