Boston is the capital and largest city in the Commonwealth of Massachusetts.[3] The largest city in New England, Boston is considered the unofficial economic and cultural center of the entire New England region.[4] The city, which had an estimated population of 596,763 in 2006, lies at the center of the Boston–Cambridge–Quincy metropolitan area—the 11th-largest metropolitan area (5th largest CSA) in the U.S. with a population of 4.4 million. Residents of Boston are referred to as Bostonians.