Standard Metropolitan Statistical Area Smsa

a territorial statistical unit used in the United States for identifying and quantitatively describing urban agglomerations. All cities with a population of more than 50,000 that are not suburbs of larger cities are SMSA’s. Each SMSA includes one or more counties, selected according to such criteria as population density, level of urbanization, and strength of economic and cultural ties to the central city. In 1974, the US Bureau of the Census published data on 283 SMSA’s, showing that 70 percent of the country’s population and nearly 75 percent of the economic activity were concentrated in less than 10 percent of the country’s area. The boundaries of SMSA’s are periodically reviewed to take into account the territorial growth of suburban areas.

Metropolitan areas are similarly identified in other countries, for example, Canada.