How big is the US economy? New York City’s GDP, alone, is as big as Australia’s

Yes, the health of US cities is critical to the health of the broader US economy. As this great chart from CityLab shows, cities generate a heck of a lot of GDP growth: “More and more, the U.S. economy is defined by its metropolitan areas, which produce 90 percent of its output.” (The numbers in the chart by the way, are in billions of dollars. As Ryan Avent has written:

The American economy’s famous upward mobility rested in part on middle-class access to rich, entrepreneurial cities. This machinery is breaking down, however, mostly because upward mobility strikes too many residents of rich places as too messy a pursuit to accommodate. During the Industrial Revolution, for instance, millions of workers flooded into fast-growing cities. This produced slums, but it also allowed poor workers to take advantage of opportunities in new industries, a process that helped create the middle class.

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