Metropolitan Statistical Area
Metropolitan Statistical Area (MSA). A geographic entity defined by OMB for use by Federal statistical agencies in collecting, tabulating, and publishing Federal statistics. A Metropolitan Statistical Area contains a core urban area of 50,000 or more population, and a Micropolitan Statistical Area contains an urban core of at least 10,000 (but fewer than 50,000) population. Each metropolitan or micropolitan area consists of one or more counties and includes the counties containing the core urban area, as well as any adjacent counties that have a high degree of social and economic integration (as measured by commuting to work) with the urban core.