Economic contribution as measured by gross domestic product (GDP) across major U.S. cities is about as lopsided as the country’s distribution of wealth overall. According to 2014 statistics released by the U.S. Department of Commerce’s Bureau of Economic Analysis, the top 20 metropolitan areas represented more than 52 percent of the total country’s GDP.
GDP is a broad quantitative measure of a nation’s total economic activity. The number represents the total monetary value of all the new goods and services produced in an area, but it does have its faults: Since GDP only measures money flowing through the economy, money saving measures or secondhand, off-the-books purchases aren’t recorded. The number also doesn’t reflect equity among people within the measured area, only the total amount of money.
Despite those flaws, GDP is one of the most useful tools a country has to gauge how healthy its economy is. Going by the above map, showing that the majority of America’s economic activity skews towards just a handful of large cities (whose own wealth distribution is equally lopsided amongst their residents), maybe “healthy” isn’t the right word.