A large population nucleus and the nearby communities that have a high degree of economic and social integration with that nucleus. Each SMSA consisted of one or more entire counties (or county equivalents; in New England, cities and towns) that met specified standards pertaining to population, commuting ties, and metropolitan character. SMSAs were designated by the U.S. Office of Management and Budget. An SMSA included a city or an urbanized area (as defined by the Bureau of the Census) with a population of at least 50,000, and had a total population of at least 100,000 (75,000 in New England). The term SMSA was replaced by metropolitan statistical area (MSA) after the 1980 census. (TRB)