GDP affects the entire country not just these localities and cities network into and recruit huge areas around them. NYC isn't Boulder, CO. It has global reach,

GDP affects the entire country not just these localities and cities network into and recruit huge areas around them. NYC isn't Boulder, CO. It has global reach, and actions taken in New York can affect the movement of money all over the planet. An example, suppose somebody can suddenly afford to live in NYC, where they get a job moving commodities through an import/export business. Their contribution to NYC's GDP is minor: salary and profit on the deals they make. By getting this person into position to make these deals, American commodity producers suddenly get additional access to global markets they might not have had otherwise and suddenly corn from Stoy, Illinois is finding its way to China and Wheat from Russell, Kansas is ending up in Germany. Moving those commodities employs truckers, truck manufacturers, ship crews, cargo container companies, shipping companies, etc. and all of those additionally network and recruit other industries: fuel, navigation, refrigeration, packaging, etc. So while our NYC broker friend might only contribute a fraction of a fraction of a percent to NYC's economy (maybe not even a million dollars all told), his impact on the U.S. economy is vastly magnified. He may single-handedly connect enough sellers to enough buyers to keep hundreds of people fully employed and cause tens of millions of dollars of value to be created and distributed. The alternative to him not being in place? The crops go to waste, or the farmers are simply paid to not grow them.