A research paper by The Martin Prosperity Institute studied satellite images of the globe at night to identify the world’s top “mega-regions”. The study found a dozen of these mega-regions in North America, mainly the United States. The Raleigh and North Carolina area is included in one of these mega-regions they are labeling “Char-lanta”.
According to the study, “Char-lanta, which is home to 22 million people, takes in 45 metros, including Atlanta, Georgia; Raleigh, North Carolina; and Birmingham, Alabama. With more than a trillion in economic output, its economy is bigger that South Korea’s, placing it among the world’s fifteen largest economies.”
See the maps below of the “mega-regions” in the United States.
If you want to read more about this, an article with more in depth explanation can be found here.